1. T. S. Ismailov, Zh. Prikl. Khimii, 56 (1983) 419.
2. D. B. Goldman, J. Amer. Cer. Soc., 66 (1983) 811.
3. R. B. Chesnokova, A. A. Bondyreva, N. N. Astakhov and N. N. Zhivotenko, Zh. Neorg. Khimii, 27 (1982) 286.
4. E. Klar, in Metals Handbook, 9th Ed., 7, Powder Metallurgy, ASM, Metals Paris, Ohio, 1984, p. 52.
5. V. A. Komarov, Russian J. Phys. Chem., 27 (1953) 1748.