1. I. P. Zvyagin, Transport Phenomena in Disordered Semiconductors [in Russian], Izd. MGU, Moscow, 1984.
2. H. Graener, M. Rosenberg, T. E. Whall, and M. R. B. Jones, Philos. Mag. B 44, 389 (1981).
3. A. A. Andreev, O. A. Golikova, M. M. Kazanin et al., Fiz. Tekh. Poluprovodn. 15, 1210 (1981) [Sov. Phys. Semicond. 15, 697 (1981)].
4. N. Mott and E. Davis, Electronic Processes in Non-Crystalline Materials, Clarendon Press, Oxford, 1971; Mir, Moscow, 1982.
5. I. P. Zvyagin, Fiz. Tekh. Poluprovodn. 12, 1018 (1978) [Sov. Phys. Semicond. 12, 606 (1978)].