1. Method of Higher Harmonics in Detectoscopy (Proceedings of the All-Union Seminar, Krasnoyarsk, September 16?24, 1968) [in Russian], Institute of Physics SO AN SSSR, Krasnoyarsk (1969).
2. R. E. Ershov, Izv. Vyssh. Ucheb. Zaved., Fizika, No. 4, 52 (1966).