1. A. P. Pyatakov and A. K. Zvezdin, Usp. Fiz. Nauk 182 (6), 593 (2012).
2. N. N. Krainik, N. P. Khuchua, A. A. Berezhnoi, and A. G. Tutov, Fiz. Tverd. Tela 7 (1), 132 (1965).
3. V. V. Zhdanova, Fiz. Tverd. Tela 7 (1), 143 (1965).
4. G. A. Smolenskii and V. M. Yudin, Fiz. Tverd. Tela 6 (12), 3668 (1965).
5. J. P. Patel, A. Singh, and D. Pandey, J. Appl. Phys. 107, 104115 (2010).