1. V. K. Malinovskii, O. A. Gudaev, V. A. Gusev, and S. I. Demenko, Photoinduced Phenomena in Sillenites [in Russian] (Nauka, Novosibirsk, 1990).
2. Sh. M. Efenliev, V. E. Bagiev, A. Ch. Zeinally, and V. M. Skoricov, Phys. Status Solidi A 50, Pk141 (1978).
3. S. Z. Swartz and V. E. Wood, Condens. Matter News 1, No. 5, 4 (1992).
4. A. V. Suikovskaya, Chemical Methods of Producing Thin Transparent Films [in Russian] (Khimiya, Leningrad, 1971).
5. Handbook of Acoustic Crystals [in Russian], edited by M. P. Shaskol’skaya (Nauka, Moscow, 1982).