The New Palgrave Dictionary of Economics Online
http://www.dictionaryofeconomics.com/

The world’s most extensive and authoritative economics reference resource. The New Palgrave Dictionary of Economics, 2nd edition, edited by Steven N. Durlauf and Lawrence E. Blume, contains over 1,850 articles by more than 1,500 of the world’s leading economists. Find out more about the Dictionary, take a tour of the online edition, or browse a sample article. Their Resources section contains additional material to help you make the most of the Dictionary. This has been added to Reference Resources Subject Tracer™ Information Blog.