1. K. KOMEYA and H. INOUE,Trans. J. Br. Ceram. Soc. 70 (1971) 107.
2. H. INOUE, A. TSUGE and K. KOMEYA, presented at the Fall Meeting of the Japanese Society of Powders and Power Metals, Kanazawa, Japan, 1973.
3. K. KOMEYA, H. INOUE and A. TSUGE,Yogyo-Kyokai-Shi,89 (1981) 58.
4. R. W. NURSE, J. H. WELCH and A. J. MAJUMDAR,Trans. Br. Ceram. Soc. 64 (1965) 416.