Thread:Extension talk:Cite/Popups with references/reply

if you mean enwiki when you say "like on wikipedia", it's done via gadget, namely en:MediaWiki:Gadget-ReferenceTooltips.js, which is explained in Reference Tooltips. there are some other options, specifically one lighter with less features: he:Mediawikiי:Gadget-CiteTooltip.

peace.