Links to language learning resources on the Web Language learning sites - listing of general language learning resources Reference sites - listing of reference sites as well as sites that contain links to reference sites. Reference sites are sites that you would use in the upper main window of Lex. Sites to work on - sites that you would use in the lower main window of Lex. The easiest way to find interesting sites to work on is through search engines. This list is just a complement to that.