Wikipedia Needs References tells you when a page you are viewing could be a good reference to a Wikipedia article.
Wikipedia Needs References makes editing Wikipedia an easy and fun part of your web browsing experience. It is perfect for beginner editors looking for simple edit tasks. Here's how it works: whenever you visit a page from set of reputable websites, this extension will attempt to match its contents with Wikipedia articles that are known to need better references. It will let you know if it finds any -- look for the icon next to the URL bar. You can then visit one of these articles and improve it! This extension is only active on whitelisted websites and does not change your browsing experience on other pages. The whitelist contains some news websites by default and can be configured via the options page in the extension.