1. A. I. Lebedev, Fiz. Tverd. Tela (St. Petersburg) 51(2), 341 (2009) [Phys. Solid State 51 (2), 362 (2009)].
2. G. A. Smolenskiĭ, Dokl. Akad. Nauk SSSR 70, 405 (1950).
3. P.-H. Sun, T. Nakamura, Y. J. Shan, Y. Inaguma, and M. Itoh, Ferroelectrics 217, 137 (1998).
4. Y. J. Shan, H. Mori, R. Wang, W. Luan, H. Imoto, M. Itoh, and T. Nakamura, Ferroelectrics 259, 85 (2001).
5. M. E. Guzhva, V. V. Lemanov, and P. A. Markovin, Fiz. Tverd. Tela (St. Petersburg) 43(11), 2058 (2001) [Phys. Solid State 43 (11), 2146 (2001)].