1. V. V. Obukhovskii and V. V. Lemeshko, Pis′ma Zh. Tekh. Fiz., 11, 1389–1393 (1985).
2. V. V. Obukhovskii, A. V. Stoyanov, and V. V. Lemeshko, Kvantovaya Elektron. (Moscow), 14, No. 1, 113–121 (1987).
3. V. V. Obukhovskii and A. V. Stoyanov, Opt. Spektrosk., 58, No. 2, 378–385 (1985).
4. V. I. Stroganov, N. V. Marchenkov, and A. V. Emel′yanenko, Opt. Spektrosk., 67, No. 3, 982–985 (1989).
5. V. A. Maksimenko, A. V. Syui, and Yu. M. Karpets, Photo-induced Processes in Lithium Niobate Crystals [in Russian], Fizmatlit, Moscow (2008).