1. A. M. Guseinov and T. I. Sadykhov, in Electrophysical Properties of Semiconductors and Gas Discharge Plasma, Collected vol. (AGU, St.-Petersburg, Baku, 1989), p. 42 [in Russian].
2. N. F. Kovtonyuk and Yu. A. Kontsevoi, Measurement of Parameters of Semiconductor Materials (Metallurgiya, Moscow, 1970) [in Russian].
3. G. Lampert and P. Mark, Injection Currents in Solids (Academic, New York, 1970; Mir, Moscow, 1973), ch. 2, p. 25.
4. R. Smith, Semiconductors (Cambridge Univ., Cambridge, 1959; Mir, Moscow, 1982).
5. M. K. Sheinkman and A. Ya. Shik, Sov. Phys. Semicond. 10, 128 (1976).