1. A. A. Grigor’kin and S. M. Dunaevskii, Fiz. Tverd. Tela 22, 557 (2007).
2. L. I. Magarill and M. V. Jentin, Pis’ma Zh. Eksp. Teor. Fiz. 77, 249 (2003) [JETP Lett. 77, 493 (2003)].
3. I. A. Dmitriev and R. A. Suris, Fiz. Tekh. Poluprovodn. 36, 1449 (2002) [Semiconductors 36, 1364 (2002)].
4. N. G. Galkin, V. A. Margulis, and A. V. Shorohov, Fiz. Tverd. Tela 43, 511 (2001) [Phys. Solid State 43, 530 (2001)].
5. V. A. Margulis, N. F. Pavlova, and A. V. Shorohov, Fiz. Tverd. Tela 48, 880 (2006) [Phys. Solid State 48, 935 (2006)].