http://pinoyathletics.com/2012/09/16/evolution-of-the-high-jump/
Diagrams of evolution of the high jump.
Diagrams of evolution of the high jump.
Jesus Dapena is the authority on everything related to the high jump.
A comprehensive mechanical analysis of high jump technique evolution:
http://www.indiana.edu/~sportbm/p391-presentations/hjevo-isbs.ppt
A "Science Friday" video explaining high jump technique:
http://www.sciencefriday.com/video/07/20/2012/getting-a-leg-up-high-jump-explained.html