1. B. S. Kerner and V. V. Osipov, Autosolitons (Nauka, Moscow, 1991).
2. B. S. Kerner and V. F. Sinkevich, Pis’ma Zh. Éksp. Teor. Fiz. 36, 359 (1982) [JETP Lett. 36, 436 (1982)].
3. V. N. Vashchenko, B. S. Kerner, V. V. Osipov, and V. F. Sinkevich, Fiz. Tekh. Poluprovodn. (Leningrad) 24, 1705 (1990) [Sov. Phys. Semicond. 24, 1065 (1990)].
4. A. M. Musaev, Fiz. Tekh. Poluprovodn. (St. Petersburg) 33, 1183 (1999) [Semiconductors 33, 1076 (1999)].
5. A. G. Milnes, Deep Impurities in Semiconductors (Wiley, New York, 1973; Mir, Moscow, 1977).