1. V. A. Sokolov and A. N. Gorban, Luminescence and Adsorption [in Russian], Nauka, Moscow (1969).
2. Th. Wolken stein, A. N. Gorban, and V. A. Sokolov, Radical-Recombination Luminescence in Semiconductors [in Russian], Nauka, Moscow (1976).
3. V. V. Malakhov, G. P. Peka, and Th. Wolkenstein, J. Lumin., 5, 252 (1972).
4. V. V. Malakhov, G. P. Peka, and Th. Wolkenstein, J. Lumin., 5, 261 (1972).
5. G. P. Peka and Yu. I. Karkhanin, Dokl. Akad. Nauk SSSR, 141, 60 (1961).