1. H. D. Eberhart(1947 ) Report on the Fundamental Studies of Human Locomotion and other information relating to design of artificial limbs, Prosthetic devices research project, College of Engineering Research, University of California, Berkeley, California.
2. Symmetrical Gaits of Horses
3. M. Hildebrand(1968 ) Private communication. Not yet published.
4. The Dynamics Of Quadrupedal Walking