1. A. Yu. Leshko, A. V. Lyutetskii, N. A. Pikhtin, and G. V. Skrynnikov, Fiz. Tekh. Poluprovodn. (St. Petersburg) 34, 1457 (2000) [Semiconductors 34, 1397 (2000)].
2. D. A. Vinokurov, V. A. Kapitonov, D. N. Nikolaev, et al., Fiz. Tekh. Poluprovodn. (St. Petersburg) 35, 1380 (2001) [Semiconductors 35, 1324 (2001)].
3. E. G. Golikova, V. A. Kureshov, A. Yu. Leshko, et al., Fiz. Tekh. Poluprovodn. (St. Petersburg) 34, 886 (2000) [Semiconductors 34, 853 (2000)].
4. D. A. Livshits, A. Yu. Egorov, I. V. Kochnev, et al., Fiz. Tekh. Poluprovodn. (St. Petersburg) 35, 380 (2001) [Semiconductors 35, 365 (2001)].
5. P. V. Bulaev, V. A. Kapitonov, A. V. Lyutetskii, et al., Fiz. Tekh. Poluprovodn. (St. Petersburg) 36, 1144 (2002) [Semiconductors 36, 1065 (2002)].