1. E. Orowan:Proc. Phys. Soc. (London), 1940, vol. 52, p. 8.
2. I. Gupta and J. C. M. Li:Met. Trans., 1970, vol. 1, p. 2323.
3. K. M. Prewo: Ph. D. Dissertation, Columbia University, 1969.
4. B. C. Taylor:Proc. Conf Prop. Matls. at High Rates of Strain, Inst. Mech. Engrs., London, 1957.
5. W. B. Morrison and R. C. Glenn: Quoted by K. M. Prewo in Ref. 3. Ph. D. Dissertation, Columbia University.