1. R. W. Cahn,J. Phys. Coll. 43 (1982) C9?55.
2. P. G. Zielinski andH. Matyja, Proceedings RQ2 Sec. I edited by N. J. Grant and B. C. Giessen (Massachusetts Institute of Technology, Cambridge, Massachusetts, 1976) p. 237.
3. A. R. Yavari, P. Hicter andP. Desre,J. Chim. Phys. 79 (1982) 579.
4. P. Ramachandrarao,Z. Metallkde 71 (1980) 172.
5. I. W. Donald andH. A. Davies,J. Non-Cryst. Solids 30 (1973) 77.