1. S. Prochazka, Proceedings of the Conference on Ceramics for High Performance Applications, Hyannis, Mass. (1973), edited by J. J. Burke, A. E. Gorum and R. N. Katz, (Brook Hill, Boston, 1975) p. 220.
2. J. A. Coppola and C. H. Mcmurtry, Presented at the American Chemical Society Symposium, ?Ceramics in the Service of Man?, Washington, D.C. (1976).
3. M. H. Hon and R. F. Davis, J. Mater. Sci. 14 (1979) 2411.
4. R. N. Ghoshtagore and R. L. Coble, Phys. Rev. 143 (1966) 623.
5. J. D. Hong, Ph.D. thesis, North Carolina State University, (1978).