links

http://www.b-boys.com/classic/hiphoptimeline.html#1973

http://www.mrwiggles.biz/hip_hop_history.htm

http://www.daveyd.com/raphist1.html

http://rap.about.com/od/hiphop101/a/hiphoptimeline.htm

http://www.scaruffi.com/history/hiphop.html