1. V. I. Gol’danskii and E. P. Prokop’ev, Fiz. Tverd. Tela,8, 515 (1966).
2. V. I. Gol’danskii, The Physical Chemistry of the Positron and Positronium [in Russian], Nauka, Moscow (1968).
3. U. A. Arifov and P. U. Arifov, The Physics of Slow Positrons [in Russian], Fan, Tashkent (1971).
4. U. A. Arifov, P. U. Arifov, R. M. Gataullin et al., Atomic Systems and Positron Annihilation [in Russian], Fan, Tashkent (1972).
5. P. U. Arifov, N. Yu. Arutyunov, E. P. Prokop’ev, et al., Quantum Properties of Atoms and Ions and Positron Diagnostics [in Russian], Fan, Tashkent (1975).