1. A. A. Bugai, V. M. Maksimenko, B. M. Turovskii, L. I. Khirunenko, V. I. Shakhovtsov, and N. I. Gorbacheva, Fiz. Tekh. Poluprovodn. 18, 2020 (1984) [Sov. Phys. Semicond. 18, 1260 (1984)].
2. I. G. Atabaev, M. S. Saidov, L. I. Khirunenko, V. I. Shakhovtsov, V. K. Shinkarenko, L. I. Shpinar, and A. Yusupov, Fiz. Tekh. Poluprovodn. 21, 570 (1987) [Sov. Phys. Semicond. 21, 350 (1987)].
3. L. I. Khirunenko, V. I. Shakhovtsov, V. K. Shinkarenko, L. I. Shpinar, and I. I. Yakovlets, Fiz. Tekh. Poluprovodn. 21, 562 (1987) [Sov. Phys. Semicond. 21, 345 (1987)].