1. V. V. Kaminskii and S. M. Solov’ev, Fiz. Tverd. Tela (St. Petersburg) 43(3), 423 (2001) [Phys. Solid State 43, 439 (2001)].
2. V. V. Kaminski $$\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}$$ , in Proceedings of the International Workshop on Results of Fundamental Research for Investments’ 2001 “Nonconventional and Renewable Energy Sources,” St. Petersburg, 2001, p. 45.
3. V. V. Kaminskii, L. N. Vasil’ev, M. V. Romanova, and S. M. Solov’ev, Fiz. Tverd. Tela (St. Petersburg) 43(6), 997 (2001) [Phys. Solid State 43, 1030 (2001)].
4. A. V. Golubkov, E. V. Goncharova, V. A. Kapustin, et al., Fiz. Tverd. Tela (Leningrad) 22(12), 3561 (1980) [Sov. Phys. Solid State 22, 2086 (1980)].
5. A. V. Golubkov, N. F. Kartenko, V. M. Sergeeva, and I. A. Smirnov, Fiz. Tverd. Tela (Leningrad) 20(1), 228 (1978) [Sov. Phys. Solid State 20, 126 (1978)].