1. M. M. Gaidukov, A. B. Kozyrev, V. N. Osadchii, and V. F. Vratskikh, Pis’ma Zh. Tekh. Fiz. 20(18), 86 (1994) [Tech. Phys. Lett. 20, 761 (1994)].
2. P. Grosse, Free Electrons in Solids, Mir, Moscow (1982).
3. A. I. Golovashkin, E. V. Ekimov, S. I. Krasnosvobodtsev et al., Physica C 162–164, 715 (1989).
4. T. M. Burbaev, G. A. Kalyuzhnaya, V. A. Kurbatov, V. S. Nozdrin, and N. A. Penin, Fiz. Tverd. Tela (St. Petersburg) 39, 228 (1997) [Phys. Solid State 39, 200 (1997)].
5. V. Ambegaokar, B. I. Halperin, D. R. Nelson, and E. D. Siggia, Phys. Rev. Lett. 40, 783 (1978).