1. A. M. Kosevich, B. A. Ivanov, and A. S. Kovalev, Nonlinear Waves of Magnetization. Dynamical and Topological Solitons (Naukova Dumka, Kiev, 1983), p. 189.
2. V. P. Kravchuk and D. D. Sheka, Fiz. Tverd. Tela 49, 1834 (2007) [Phys. Solid State 49, 1923 (2007)].
3. A. S. Kovalev and Ya. E. Prilepskii, Fiz. Nizk. Temp. 28, 1292 (2002) [Low Temp. Phys. 28, 921 (2002)].
4. V. F. Shkar, E. I. Nikolaev, V. N. Sayapin, et al., Fiz. Tverd. Tela 46, 1043 (2004) [Phys. Solid State 46, 1073 (2004)].
5. R. A. Silin and V. P. Sazonov, Retarding Systems (Sov. Radio, Moscow, 1966), p. 632 [in Russian].