1. S.R. Goodman: U.S. Steel Research Laboratory, Monroeville, PA, unpublished research, 1980.
2. D. C. Ludwigson: U. S. Steel Research Laboratory, Monroeville, PA, unpublished research, 1972.
3. K. Matsudo: Technical Research Center, Nippon Kokan K. K., Fukuyama, Japan, private communication, 1981.
4. E. O. Hall:Yield Point Phenomena in Metals and Alloys, Plenum Press, New York, NY, 1970, pp. 1–126.
5. Reference 4, pp. 30–31.