1. B. M. Bul and V. A. Kudryavtsev, Fiz. Tekh. Poluprovod.,5, 11, 5 (1971).
2. S. I. Berul', V. B. Lazarev, and A. V. Salov, Zh. Neorg. Khim.,16, 3363 (1971).
3. S. I. Berul', V. B. Lazarev, and A. V. Salov, Zh. Neorg. Khim.,16, 2012 (1971).
4. V. B. Lazarev, K. E. Spear, and A. B. Salov, Mat. Res. Bull.,7, No. 5, 417 (1972).
5. V. G. Kuznetsov, A. S. Kanishcheva, and A. V. Salov, Zh. Neorg. Khim.,18, 247 (1972).