1. Yu. M. Karpets, V. A. Maksimenko, O. V. Skobletskaya, et al., Opt. Spektrosk. 91, 968 (2001) [Opt. Spectrosc. 91, 907 (2001)].
2. V. V. Obukhovskii, Doctoral Dissertation (Kiev State Univ., Kiev, 1989).
3. R. Grousson, S. Mallick, and S. Odulov, Opt. Commun. 51, 342 (1985).
4. Yu. S. Kuz’minov, Electro-Optic and Nonlinear Optical Lithium Niobate Crystals (Nauka, Moscow, 1987) [in Russian].
5. M. P. Petrov, S. I. Stepanov, and A. F. Khomenko, Photorefractive Crystals in Coherent Optics (Nauka, St. Petersburg, 1992) [in Russian].