1. L. M. Brekhovskikh, Waves in Layered Media (Nauka, Moscow, 1973; Academic, New York, 1980).
2. F. G. Bass, A. A. Bulgakov, and A. P. Tetervov, High-Frequency Properties of Semiconductors with Superlattices (Nauka, Moscow, 1989) [in Russian].
3. R. A. Silin, Usp. Fiz. Nauk 175, 562 (2006) [Phys. Usp. 49, 542 (2006)].
4. S. I. Maslovskii, Pis’ma Zh. Tekh. Fiz. 29(1), 69 (2003) [Tech. Phys. Lett. 29, 32 (2003)].
5. I. B. Vendik, O. G. Vendik, and M. S. Gashinova, Pis’ma Zh. Tekh. Fiz. 32(10), 30 (2006) [Tech. Phys. Lett. 32, 429 (2006)].