1. I. P. Kazakov, A. V. Klekovkin, V. A. Tsvetkov, et al., Kratkie Soobshcheniya po Fizike FIAN 45(12), 40 (2018) [Bulletin of the Lebedev Physics Institute 46, 5 (2019)].
2. D. S. Kozyrev and T. M. Burbaev, St. Petersburg Polytechnical University Journal: Physics and Mathematics 3(177), 60 (2013).
3. T. M. Burbaev, M. N. Gordeev, D. N. Lobanov, et al., Pisma Zh. Eksp. Teor. Fiz. 92, 341 (2010) [JETP Lett. 92,305 (2010)].
4. N. N. Sibeldin, Zh. Eksp. Teor. Fiz. 149, 678 (2016) [J. Exp. Theor. Phys. 122, 587 (2016)].
5. H. Lafontaine, D. C. Houghton, N. Rowell, et al., J. Cryst. Growth 157, 57 (1995).