1. 1K. H. Jack, F. P. Glasser, and P. E. Potter ; pp.204 -21 inHigh Temperature Chemistry of Inorganic and Ceramic Materials . The Chemical Society, London, 1977 .
2. 2K. H. Jack, and A. M. Alper ; pp.241 -85 inPhase Diagrams; Materials Science and Technology , Vol. 6 -V . Academic Press, New York, 1978 .
3. 3P. H. A. Roebuck, and D. P. Thompson , pp.222 -28 in Ref. 1.
4. 5D. P. Thompson, and F. L. Riley ; pp.129 -35 inNitrogen Ceramics . International Publishing, Reading, Mass, 1977 .