EARLY KEYNESIAN ECONOMICS
www.econlib.org/library/Enc/KeynesianEconomics.html as described by Alan S. Blinder in The Concise Encyclopedia of Economics
http://distance-ed.bcc.ctc.edu/econ100/ksttext/keynes/keynes.htm on the Keynesian revolution
http://en.wikipedia.org/wiki/Keynesian_economics on the historical background of Keynesian Economics
www.investopedia.com/terms/k/keynesianeconomics.asp on the view that Keynesian is a theory stating that active government intervention in the marketplace and monetary policy is the best method of ensuring economic growth and stability
"Keynesian Theory in Relation to Classical Theory" by John Maynard Keynes in Paul Samuelson, et. al. 1952 pages 442-446.