Reading/Web/Desktop Improvements/Frequently asked questions/es





¿Cómo activar o desactivar Vector 2022?


¿Cómo puedo desactivarlo en una o en todas las wikis de Wikimedia?
En primer lugar, comprueba si te has conectado a tu cuenta. Los usuarios desconectados no pueden cambiar de skin.

Ver también:
 * ¿Por qué se llaman Vector (2022) y Versión heredada de Vector (2010)?



¿Por qué el enlace de desactivación no está disponible para las personas no lo logadas?
Esto se debe a la capacidad limitada de nuestros servidores. Los usuarios desconectadas pueden utilizar extensiones del navegador que les permitan personalizar su interfaz, o pueden crear una cuenta.

Ver también:


 * Why are there no preferences for anonymous users?



¿Cómo puede Vector 2022 convertirse en la opción predeterminada en mi wiki?
Contáctanos. Presentaremos el proyecto a tu comunidad y comenzaremos una conversación.



¿Cómo puedo habilitar Vector 2022 para mí?
Si quieres ver nuestras mejoras,


 * 1) Asegúrate de haber descargado $1
 * 2) Añade las siguientes líneas en tu $1:

¡Nos alegra saber que aprecia nuestras mejoras!



¿Cómo personalizar Vector 2022?


¿Por qué no se ofrecen alternativas para elegir entre diferentes versiones de las funcionalidades?
Eso sería demasiado complicado de mantener y desarrollar.

Cada preferencia es algo así como un cruce de caminos en el que los usuarios pueden elegir entre distintas opciones. Muchas opciones indican muchas combinaciones. Las preferencias nos harían responsables de todas las combinaciones. Tendríamos que mantenerlas y, además, en el caso de construir nuevas funcionalidades, comprobar si éstas son compatibles con cada una de las combinaciones. Por ahora, no podemos asumir eso.

En su lugar, damos a las comunidades la opción de crear gadgets, scripts de usuario y configuraciones individuales. Como siempre, proporcionamos el espacio para la creación ascendente, y ayudamos a los usuarios técnicos a mantener su código.

Ver también: 
 * Convertirlo en una preferencia de usuario/a

¿Por qué no hay preferencias para los usuarios anónimos?
Las preferencias anónimas harían que las páginas se cargaran muy lentamente.

La mayor parte del tráfico proviene de personas desconectadas. Para ello, disponemos de algunos "servidores de caché" que sólo guardan y envían "instantáneas" de las páginas web. Estas "instantáneas" tienen una antigüedad de hasta 7 días, sustituyen a la generación de páginas web y son las mismas para todos los usuarios desconectados. Esto nos permite una carga rápida de las páginas.

Las preferencias requieren la generación de diferentes versiones de las páginas web. Ofrecer esta posibilidad a las personas no connectadas sobrecargaría nuestros servidores. No queremos hacer eso porque tenemos que reducir la fragmentación de la caché.

La única forma de proporcionar preferencias a los usuarios desconectados ahora que la configuración se cargue siempre después de la página. Esto requiere [1$ más de tiempo de carga] y tiene un aspecto extraño. Por ejemplo, si una persona que haya cerrado la sesión viera el modo oscuro en acción, inmediatamente después de cargar cada página, vería primero la interfaz luminosa durante un breve momento, y luego la interfaz se volvería oscura.

Para contextualizar, la única razón por la que tenemos preferencias para los usuarios registrados es que no les servimos esas "instantáneas". Y esto se debe a que el tráfico procedente de los usuarios registrados es bajo.

Ver también:


 * Cómo un nuevo centro de datos en Singapur está ayudando a la gente a acceder a Wikipedia en todo el mundo
 * Construyendo DReaMeRS: Cómo y por qué abrimos un centro de datos en Francia
 * Por qué importa el rendimiento



¿Qué hacemos para las personas editoras que necesitan herramientas y funciones específicas?

 * Nos ponemos en contacto con voluntarios con conocimientos técnicos para garantizar la compatibilidad con la versión anterior. Les pedimos que comprueben el código que han escrito, y les ofrecemos ayuda si el código necesita cambios.
 * Hacemos posible la configuración y personalización de nuestros cambios. Colaboramos con voluntarios con conocimientos técnicos que quieran crear nuevos gadgets y scripts de usuario.
 * No sustituimos el trabajo de las personas voluntarias con conocimientos técnicos. En principio, no realizamos ediciones de plantillas ni creamos nuevos gadgets, pero podemos asesorar cuando sea necesario.



¿Arregláis los accesorios que no funcionan con vuestros cambios?
Depende.

Ayudamos a las personas voluntarias a reparar los accesorios y user scripts. En ocasiones, los reparemos nosotros mismos. Pero en general, trabajamos en el propio MediaWiki. Los accesorios y los user scripts son escritos y mantenidos por personas voluntarias. Por su naturaleza, éstas son siempre menos estables y predecibles.

¡Si no estás seguro de cómo solucionar un problema con un script o gadget - contacta con nosotros! Haremos todo lo posible por aconsejarle sobre posibles soluciones.

Ver también:


 * Tecnología en Meta-Wiki - aquí también puedes pedir soporte técnico
 * 1 - una propuesta de política sobre las funciones y responsabilidades relacionadas con los gadgets y los scripts de los usuarios

 ¿Por qué no usar solo las funciones beta? Las funciones beta están disponibles solo para usuarios registrados, y las mejoras están destinadas a servir a nuestros lectores y usuarios no registrados también. Por lo tanto, usar solo las funciones beta nos brindaría comentarios de un tipo de usuario muy específico que no es representativo de toda nuestra base de usuarios. Y además, deseamos recibir los comentarios de los lectores y usuarios anónimos de las primeras implementaciones. Por lo tanto, el uso de las funciones beta sólo nos daría información de un tipo de usuario muy específico que no sería representativo de toda nuestra base de usuarios. Y además, también queremos recibir los comentarios de las personas lectoras y usuarios anónimos.



¿Qué clases de CSS deben utilizarse para personalizar Vector 2022?

 * 1$ para ambas skins
 * skin-vector-legacy para Versión heredada de Vector (2010)
 * skin-vector-2022</tt> para Vector 2022

<span id="How_to_restore_the_full_width?">

¿Cómo restaurar el ancho completo?
See also:


 * Modifications of Vector 2022: new gadgets and user scripts

How to disable the sticky elements?
Add the following CSS code to your global.css:


 * Header – add
 * ToC – add

How to restore the old table of contents?
Use the following JavaScript code:

How to make the button with language links appear at the top of the main page?

 * 1) Ask your community to agree to set up the main page heading. (See our explanation why this is a good idea.)
 * 2) The heading will be displayed in Vector 2010, Minerva, Timeless, and Vector 2022. It will not be visible in Monobook.
 * 3) The heading can be configured by edits to MediaWiki:Mainpage-title-loggedin for logged in users and MediaWiki:Mainpage-title for logged out users. For mobile logged in users, MediaWiki:wikimedia-mobile-mainpage-title-loggedin is used. See the details about the main page heading settings.
 * 4) Test what the main page looks like and work with the button at the top by adding the ?vectorlanguageinmainpageheader=1</tt> parameter to the URL. See the example on the Icelandic-language Wikipedia. Note that the Icelandic-language Wikipedia hasn't the heading set up, so only the button appears.
 * 5) Contact us and ask us to move the button to the top.
 * 6) We will change the settings for your wiki.
 * 7) When we do this, the button will be visible at the top of the page in Vector 2022. In other skins, the list with language links will be displayed in the standard place which varies by skin.

How to restore the previous user menu?
It's not possible to do that currently.

How to change the logo to a temporary one?
The logo in Vector 2022 is made of 3 elements, each can be changed independently with CSS.
 * To change the icon image (e.g. globe on Wikipedia):
 * To change the wordmark (e.g. the word "Wikipedia"):
 * To change the tagline (e.g. the words "The free encyclopedia"):

How can I contact your team?
Choose one of the following options:
 * Talk page of the main page of the project (you can write in any language)
 * Phabricator task with the Desktop Improvements project tag
 * Contact our Community Relations Specialist: SGrabarczuk (WMF) sgrabarczuk@wikimedia.org
 * Contact one of our ambassadors:
 * French and Italian ambassador: Patafisik (WMF) patafisik-ctr@wikimedia.org
 * Spanish ambassador: Zapipedia (WMF) izapico-ctr@wikimedia.org
 * Vietnamese ambassador: Bluetpp (WMF) ppham-ctr@wikimedia.org
 * Farsi ambassador Mehran (WMF) mehran@wikimedia.org

How can I follow your activities?

 * Subscribe to our newsletter. Instead of messages on your talk page, you will be receiving notifications about the updates.
 * Watch our Updates and Talk to Web pages.

Do you host or attend online meetings?
Yes!

We organize open online meetings for the communities (office hours). At these meetings, Olga (our product manager) makes presentations about the recent developments. Next, community members can ask any questions about the project.

We are also open to invitation to any community event online. These may be local, country-wide, or international meetings.



Is this a redesign?
No.

A redesign would be a single major change which affects how the site works. In the case of this project we are making a series of changes that do not remove any of the currently available tools. Each feature is a separate small project, joined together by a cohesive visual design.

What is the timeline of this project?
We have been working on Vector 2022 (originally known as modern Vector) since 2019. The deadline to build everything we've planned so far is August/September 2022. Currently, we inform about our intention to introduce Vector 2022 on more wikis. Vector 2022 isn't "beta" anymore. It's more like a bit less than a Good Article. We ask the communities what should be done to make the skin better.

See also:


 * How can the changes be made on my home Wikimedia wiki?

Why do you use the word Improvements?
Because we have data indicating that the changes are for the better:


 * 1) We identified problems through research with both readers and editors. During this phase, in 2019, we studied the way people used the sites and identified the largest usability issues. We also identified issues to exploring the site further, becoming more engaged with reading or editing. We did this by interviewing readers and editors across multiple countries, locations, and languages. See: Research and design: Phase 1, Research and design: Phase 2.
 * 2) We built and tested prototypes. We built out the ideas of each feature and began showing them to the users. Each feature was tested with readers and editors through interviews and wider rounds of prototype testing. For testing with editors, we used central notice banners. We displayed them across multiple language and Wikimedia projects so that we can get a wide and diverse audience. Each prototype was tested by approximately 200 editors on average. (Example)
 * 3) We refined and built our features. We took the feedback from the prototype testing and refined or changed the prototypes accordingly. In some cases, we asked for additional feedback to ensure we're making the right decisions.
 * 4) We contacted various wikis asking to join the early adopters ("pilot wikis"). This is the "beta" phase. On these wikis, we perform quantitative tests for whether each feature works as expected.
 * 5) We perform A/B testing on logged-in users. Unfortunately, we are not able to perform these on logged-out users. This is why we make before and after comparisons.
 * 6) When we have the test results, we compare the results with the criteria of success we have previously defined. If we get negative results from our test, we change the feature and test again.
 * 7) During this phase, we also monitor usage across all wikis, where many account holders are already using Vector 2022.

See also:


 * An encyclopedic article: Iterative and incremental development
 * A blog post: The iterative design of the Vector interface: the case of moving interlingual links

Why do you use this naming: Vector 2022 and legacy Vector?
The new skin is a continuation of many of the ideas in the original Vector skin. It is being built using the code the Vector skin uses. We wanted to maintain functional and visual continuity. Everything built and meant for legacy Vector should be working with our changes, or can be configured to do so fairly easily.

The version built in 2010 and developed until 2019 has been frozen. In other words, we will keep and maintain it, but will not be building new features for it.

The name Vector 2022 is purely a technical artifact which marks when the new Vector was available to third parties. (Third parties mean those who install MediaWiki). Despite being on French Wikipedia since 2020, it's not been supported for third parties until 2022.

On each wiki, the skin name can be overriden by changing MediaWiki:Skinname-vector-2022. However, this may cause confusion since it won't change the associated skin key that is used for site and user styles.

See also:


 * What CSS classes should be used?

Will you remove legacy Vector?
No.

Legacy Vector will continue to be available as an option in Preferences, similar to other skins that have been default in the past, such as Monobook.

On which wikis have you tested these changes?
The pilot wikis where we have been testing Vector 2022 have been:


 * Adicionalmente:
 * Office Wiki
 * 
 * MediaWiki wiki
 * Wikimedia Foundation Governance wiki
 * Collab wiki
 * Strategy wiki



Are these changes made for readers, and not for editors?
Not exactly.

Our team (Web, formerly Reading Web) works on the reading (viewing) experience on desktop and mobile browsers. Those who both view and edit, and those who view but do not edit, are one large group of the interface users. We work for all of them, bearing in mind that new and advanced editors have specific needs.

The goal of this very project is to improve the reading experience on desktop without making editing more difficult.

That said, our movement strategy recommendations implore us to improve our user experience in an inclusive manner. In this spirit, the project has a specific goal of ensuring the free knowledge grows equitably in the future. When building, we made sure to collect the voices of readers from different demographics and geographies. We also want to make their opinions a focus when defining what we were to work on, and evaluating whether a given idea was able to satisfy their needs.

See also:


 * What do you do to ensure that the change is not half-finished?
 * What do you do for editors who need specific tools and features?
 * Past projects of the Web team

What tools are the Foundation building for editors?
At the Foundation, there are other teams working on projects dedicated specifically to editors. Among them, there are:


 * Community Tech – working on projects selected by the communities during the Community Wishlist Survey
 * Editing – working on the discussion tools
 * Growth – working on the Newcomer experience project
 * Moderator Tools – focusing on the moderation needs of medium-sized Wikimedia projects
 * Anti-Harassment Tools – working on tools for administrators, anti-vandalism patrollers

Do your changes have a negative effect on the editing statistics?
No.

We collect statistics of the editing activity on all wikis. Compared to wikis with Vector legacy (2010) as the default, on wikis with Vector 2022 as the default, there are no negative differences.

Do your changes make it more difficult to explore the community side of the wikis?
No.

Readers and new editors are intimidated by large numbers of links, options, and ways of exploring the editing (in other words, the community) side of the Wikimedia projects. This is a finding of our research.

We want more users to join the communities. We do this by limiting the number of the unhidden links, and bringing additional focus on the most relevant ones. All this is done in collaboration with the Growth and Editing teams.

See also:
 * Core Experiences
 * UX Myth #12: More choices and features result in higher satisfaction

Are you focused on Wikipedia articles?
Yes.

Wikipedia articles, as a whole, have the most part of the viewership and readership compared to other namespaces on Wikipedia or any other projects. We also make adjustments to pages from other namespaces and special pages. Pages which we have made special adjustments and configurations for include: main pages, pages specific to some sister projects, special pages, the 2010 wikitext editor, the 2017 wikitext editor, and the Visual Editor.

We have also been working with the Editing team to ensure that the work they are doing for Talk pages aligns with our work, and that special configurations for talk pages are put in place.

Have you been mindful of sister projects?
Yes!

We aim to change the basic elements of the interface. Most features work on the sister projects just as well as they improve Wikipedia. We have made sure to test and build for different sister projects from the beginning of the project, often making adjustments to the default features where necessary.

Non-Wikipedia projects, such as French Wiktionary, were also a part of our partner communities, ensuring that we have direct communication and feedback from them.

Regarding the adjustments, for example, on Wikisource, the limited width does not apply to the Page namespace provided by the Proofread extension.

Are you focused on English Wikipedia?
No.

We take into account the needs of various communities and test our changes across 30+ languages. We are also inspired by the interface and gadgets built on various wikis, for example Korean and Vietnamese Wikipedias.

What do you do to ensure that the change would work on my wiki?

 * Research we make is relevant to all wikis and includes voices from many different languages and projects.
 * We gather and incorporate feedback from the communities. Most issues are relevant to all wikis.
 * How we adjust our changes to sister projects – go to "Do you remember about sister projects?"
 * What is our approach to gadgets – go "What do you do for editors who need specific tools and features?"

What do you do to ensure that the change is not half-finished?
We make tweaks both before and after we introduce the changes on wikis to make sure they are up to the needs for individual communities. If you think your community would benefit from more adjustments and gadgets, see:


 * What do you do for editors who need specific tools and features?
 * How to customize Vector 2022?

After making these changes on all wikis, we will work on projects related to Desktop Improvements.

Have your changes been tested on users with disabilities?
Yes.

We are working with the American Foundation for the Blind. We are asking various questions related to the accessibility of Vector 2022. See more on Phabricator.

Will the wikis be less accessible for users with slow Internet connection?
No.

We want to keep the new skin similarly code-heavy to legacy Vector.

See also:
 * How can I get both the old and the new table of contents?

Are the changes inspired by mobile design?
No.

These changes are created specifically for desktop interfaces. All research and testing done for this project has been focused on desktop users only. We have, however, considered the experiences of people who use desktop in narrower screens (for example, if you have two tabs open side by side).

At this time, we do not have plans to merge the desktop and mobile experiences.

Will the new interface be responsive?
We've been working towards that goal, but it's not an official goal of the project.

If you want to make the interface responsive now and you're using Wikimedia wikis, add to your global.js.

If your community would like this to be the default, please start a conversation on your wiki, and contact us when consensus is reached. We can then make the change.

Will you build a dedicated setting for high resolutions?
We don't have plans to build a specific setting at this time. We want the experience to be optimized for the majority of users, while still providing the tools necessary at all resolutions. We believe the current version of the new skin does this successfully. That said, we encourage personal customization!

See also:


 * What do you do for editors who need specific tools and features?



Why have you replaced the area used for content by an empty space?
Reading efficiently is crucial to most people using our projects. Our goal here is to improve the readability of the content. There are several factors that affect it – i.e. font size, contrast, font, line length, and empty space.


 * Shorter lines
 * 1) When reading short lines, readers don't move their eyes too much, use the eye's muscles less intensively, thus avoiding eye strain.
 * 2) Narrow paragraphs allow readers to memorize new information better.
 * 3) On websites, there should be between 35 and 100 characters per line. Numbers closer to the smaller end are preferred.
 * 4) The overwhelming number of major websites have similar limitations on content width. For example: academic journals like Nature, news websites like The New York Times, government and intergovernmental websites like the United Nations, academic documents like LaTeX, and word processors like Google Docs and Etherpad.


 * Empty (white) space


 * 1) White space is used for the eyes' resting spots. It helps readers focus on content and increases content comprehension by 20%.
 * 2) People are able to focus more easily without the distraction of sidebars or other elements.
 * 3) We are using some of this space for other functionality. We have made the sidebar sticky, and have placed the table of contents next to the content. Also, limiting the content area gives us new options for the more distant future. Community members have suggested to put infoboxes, images, or references there. As a separate project, we will consider ways of using this space.

See also:
 * UX Myth #28: White space is wasted space

Why can’t we leave it for readers to narrow their browser windows down?
Most users don't resize their browser windows or use browser plugins to improve the design of the websites they view. Wikis should be good-looking immediately, in their basic form.

Some tables and templates don’t fit within the limited width
We should make sure that all of our content is as responsive as possible to accommodate all visitors. A large percentage of our users, who don’t have large screens and are accessing Wikipedia from their laptops, already had issues with tables and templates even before the change.

Why don’t you just make it a setting?
We want it to be default. We are building a common experience that is shared between editors and readers. This could be helpful to editors when making decisions about page layouts*. Currently an editor might be editing a page at a width of 1500px, while a reader reads it at a width of 1200px. By implementing a limited width we don’t remove this discrepancy (because there would still be variation below the max-width, for people with narrower screens), however we would be greatly limiting the range of variation.

* Note: 1024px is mentioned as a minimum size to consider in the English Wikipedia Manual of Style, though that’s not quite the same thing

Why couldn't the list of language links stay in the sidebar?
Because from the readers' perspective, the sidebar is not a place for useful links. Most readers focus on the content area. Links in the sidebar are practically hidden from their sight.

Also, we need to promote the variety of language versions of Wikimedia projects.

For more than 15 years, the list has been displayed in the sidebar. The most active users have developed muscle memory to look for that list in that place. This is why in the sidebar, we have placed a box with information about the language button being displayed in a new place.

Will the Wikidata links be closer to the list of language links?
Yes.

"", "", and "" will eventually be part of the menu activated by the language switching button ("language menu"). This is a task for the Language engineering team.

How to fix the coordinates displaying incorrectly near the languages button?
Consider pages which use page status indicators, pages which have banners or site notices, and the look of the pages at lower resolutions.

Why the button with language links doesn't appear at the top of the main page?
We have discovered that readers focus on the content page and ignore the sidebar. They will be more likely to switch between languages if the button with the language links appears at the top of the page, next to the heading.

On many wikis, headings on main pages are hidden. This is why the button with language links isn't displayed next to it. Instead, it's at the bottom of the main pages. It is possible to make it appear at the top, though.

See also:


 * How to make the button with language links appear at the top of the main page?

Why doesn't the table of contents work well on my mobile device or when I resize the browser?
Users on mobile and resized browsers account for a small fraction of page traffic. Because of this, we chose to build the feature for the majority of our users first. For narrow screens we plan to make the table of contents available as a sticky interface element that's accessible from anywhere in the page.

Note what is displayed to mobile devices differs from what you see when you resize your browser. On mobile devices, the site is currently presented as a zoomed out version of the desktop site.

Why doesn't it appear when I complete an edit?
The feature is still in development (T307251). This will be fixed before we make Vector 2022 the default on more wikis.

Is it possible to change the label indicating the top of the page? ("")
Yes.

This label should be distinct from the content headings. To do that, wikis written in different scripts (for example, Latin and Japanese) and different Wikimedia projects (Wikipedia and Wiktionary) may need to use different words and/or punctuation marks in this label. It is possible for each community to set up a label that would work just for them. This may be done by editing the page MediaWiki:Vector-toc-beginning.

How can I get both the old and the new table of contents?
This isn't possible.

We intentionally do not add the old table of contents in addition to the new sidebar location. It's a trade off. We have taken it to reduce the work involved maintaining the code and keeping the site work as good as possible. The old table of contents displayed in addition to the new one would have important technical disadvantages. It would increase the overall size of HTML, increase the storage requirement for our parser cache, and require additional CSS to render.

See also:


 * How to restore the old table of contents?

How do magic words work with this feature?
The  </tt> and   </tt> magic words will not work as the table of contents is always in the sidebar and this cannot be changed.

However, magic words relating to the presence of the table of contents, such as  </tt>, will continue to work. So will templates which then create an alternate ToC. For example, an article can disable the default ToC and apply its own if necessary.

All magic words will continue to work for other skins which render the ToC within the article.

I can't see the table of contents when the sidebar is open
This is a known problem.

This issue should only impact logged in users who have opened the sidebar. In the long term, we plan to reduce the size of this menu, and make the sidebar overlay content. Details and a prototype of how that will look can be found in T302073. This change is planned in the latter part of the year (October-December 2022). Further information can be found on the page about Page tools.

<span id="What_is_the_scope_of_the_project?"> ¿Cuál es el alcance del proyecto?

<span id="Are_you_changing_Monobook_or_Timeless?"> ¿Se verán afectados los temas Monobook o Timeless?

No.

These changes are applied to Vector only. Vector has been the default interface on Wikimedia wikis since 2010. Any other skins such as Monobook, Timeless, Minerva or Modern are not be changed at all.

While working on Desktop Improvements, we did clean up the old skins' code, though. We made it easier to roll out new changes to old skins, removed never used options, and removed 75% of the PHP code of these skins. All this had no effect on the side users interact with.

See also:


 * How and why we moved our skins to Mustache

<span id="Are_you_improving_charts,_maps,_a-/f-/o-/tmboxes,_infoboxes,_navboxes,_and_other_templates?"> ¿Mejorarás los gráficos, mapas, a- / f- / o- / tmboxes, infoboxes, navboxes u otras plantillas?

No.

We do not change anything within the light gray article content area (except for the table of contents):

Are you building the dark mode?
No, not this time.

The Desktop Improvements project provides the architectural changes needed to build dark mode. Building it would be a separate project, though. This is because that project would require significant work with the communities. Now, many templates are not compatible with dark mode. We have learned that while working on the mobile apps.

Initially, our dark mode would be based on the user's operating system preferences. We would not plan to add an in-browser toggle. The reason is we currently do not have a system in place for anonymous user preferences. This could be added at a later date, though.

<span id="What_are_the_features&#039;_success_metrics?"> ¿Cuáles son las métricas de éxito de la función?

Aumentar la utilidad entre nuestras audiencias existentes, representada por:


 * Interacciones
 * Incrementar las búsquedas por sesión en un 5% durante el transcurso del proyecto.
 * Aumentar el cambio de idioma por proyecto en un 5% durante el transcurso del proyecto.


 * Afinidad
 * Aumento de sentimientos positivos y acogedores hacia el sitio (a través de encuestas y pruebas de usuarios)
 * Aumento de los sentimientos de confianza y credibilidad (medidos a través de encuestas y pruebas de usuarios)

A medida que definamos los cambios que queremos hacer con más especificidad, ampliaremos e iteraremos en esta lista.

Referencias