1. A. Kahn-Harari (Rev. Intern. Hautes Temp. Refract. 8 [1971] 71/84).
2. A. Harari, J. Théry, M. R. Collongues (Rev. Intern. Hautes Temp. Refract. 4 [1967] 207/9).
3. Loye, P. Laruelle, A. Harari (Compt. Rend. C 266 [1968] 454/6).
4. R. Ruh, A. D. Wadsley (Acta Cryst. 21 [1966] 974/8).
5. A. Revcolevschi (Rev. Intern. Hautes Temp. Refract. 7 [1970] 73/89).