1. Joubert, J.C., Collomb, A., Elmalch, D., Le Flem, G., Daoudi, A., Olivier, G.: 1. Solid StateChem. 2 (1970) 343–346.
2. Samokhvalov, A.A., Bambunov, V.G., Volkenshtein, N. V., Zotov, T.D., Morozov, Yu.N. Simonova, Mi.: Fiz. Tverd. Tela 9 (1967) 559–563.
3. Quezel-Ambnunaz, 5., Mareschal, M.: Bull. Soc. Franc. Mineral. Crist. 86 (1963)204–205.
4. Schneider, S.J., Roth, R.S., Waning, J.L.: J. Res. Natl. Bur. Std. A65 (1961) 345–374.
5. Buisson, G., Bertaut, E.F., Maneschal, J.: Compt Rend. 259 (1964) 411–413.