1. V. P. Khvostikov, O. A. Khvostikova, P. Yu. Gazaryan, M. Z. Shvarts, V. D. Rumyantsev, and V. M. Andreev, Fiz. Tekh. Poluprovodn. 38, 988 (2004) [Semiconductors 38, 950 (2004)].
2. T. N. Danilova, B. E. Zhurtanov, A. N. Imenkov, and Yu. P. Yakovlev, Fiz. Tekh. Poluprovodn. 39, 1231 (2005) [Semiconductors 39, 1235 (2005)].
3. A. P. Astakhova, B. E. Zhurtanov, A. N. Imenkov, M. P. Mikhailova, M. A. Sipovskaya, N. D. Stoyanov, and Yu. P. Yakovlev, Pis’ma Zh. Tekh. Fiz. 33(19), 8 (2007) [Tech. Phys. Lett. 33, 809 (2007)].
4. T. I. Voronina, B. E. Dzhurtanov, T. S. Lagunova, M. A. Silovskaya, V. V. Sherstnev, and Yu. P. Yakovlev, Fiz. Tekh. Poluprovodn. 32, 278 (1998) [Semiconductors 32, 250 (1998)].
5. C. M. Ruiz, J. L. Plaza, V. Berm’udez, and E. Di’eguez, J. Phys.: Condens. Matter. 14, 12755 (2002).