1. G. H. Beall, in ?Advances in Nucleation and Crystallization in glasses? (American Ceramic Society, OH, 1971) p. 251.
2. C. J. Brinker, D. R. Ulrich and D. E. Clark (eds), ?Better Ceramics through Chemistry? (Elsevier, New York, 1984)
3. D. G. Grossman, Amer. Machin. May (1978).
4. T. Hamasaki, K. Egnchi, Y. Koyanaji, A. Matsumoto, T. Vtsunomiya and K. Koba, J. Amer. Ceram. Soc. 71 (1988) 1120.
5. V. Saraswati, to be published.