1. A. B. Kozyrev, T. B. Samoilova, A. A. Golovkov, et al., J. Appl. Phys. 84, 3326 (1998).
2. A. I. Dedyk and L. T. Ter-Martirosyan, Fiz. Tverd. Tela 39, 349 (1997) [Phys. Solid State 39, 305 (1998)].
3. A. I. Dedyk and L. T. Ter-Martirosyan, Fiz. Tverd. Tela 40, 245 (1998) [Phys. Solid State 40, 220 (1998)].
4. Yu. A. Boikov, B. M. Goltsman, V. K. Yarmarkin, and V. V. Lemanov, Appl. Phys. Lett. 78, 3866 (2001).
5. A. B. Kozyrev, O. I. Soldatenkov, and A. V. Ivanov, Pis’ma Zh. Tekh. Fiz. 24(19), 19 (1998) [Tech. Phys. Lett. 24, 755 (1998)].