1. M. W. Lindley andD. J. Godfrey,Nature 229 (1971) 192.
2. D. A. Everest andA. Kelly, 5th International Materials Symposium (University of California, Berkeley, 1971).
3. I. C. Visconti andG. A. Cooper,Nature 221 (1969) 754.
4. A. Kelly, “Strong Solids” (Oxford University Press, 1966).
5. R. A. Plenty, Tech. Kept. AFML-TR-66-356, Part III (1969).