1. and , Photoinduced Phenomena in Sillenites, Izd. Nauka, Novosibirsk 1990 (p. 160) (in Russian).
2. Optical Properties of Sillenites – Electron Structure and Optical Properties of Semiconductors, Ed. Mokslas, Vilnius 1987 (p. 41 to 124) (in Russian).
3. , , and , Avtometriya, No. 5, 38 (1981).
4. and , Avtometriya, No. 5, 34 (1983).