1. S. D. Stookey, Brit. Patent No. 752 243. (1956).
2. W. Vogel and K. Gerth, Symposium on Nucleation and Crystallization in Glasses and Metals (American Ceramic Society, Columbus, Ohio, 1962) p. 11.
3. S. M. Ohlberg, H. R. Golob and D. W. Strickler, ibid. (1962) p. 55.
4. J. W. Cahn, J. Amer. Ceram. Soc. 52 (1968) 118.
5. D. R. Uhlmann, Disc. Faraday Soc. Remarks 50 (1970) 233.