1. N. G. Basov, Quantum Electronics [in Russian], Nauka, Moscow (1987).
2. A. M. Prokhorov (ed.), Handbook of Lasers [in Russian], Sov. Radio, Moscow (1978).
3. S. A. Akhmanov and R. V. Khokhlov, Problems in Nonlinear Optics [in Russian], VNITI (All-Union Institute of Scientific and Technical Information), Moscow (1965).
4. C. Townes et al., Proc. Enrico Fermi International School, New York (1964).
5. N. Bloembergen, Nonlinear Optics, Benjamin-Cummings, Menlo Park, CA (1965).