1. , , and , Luminescence and Point Defects in Crystals, VINITI Dep. No 2513–78, Moscow 1978 (p. 37) (in Russian).
2. , , , and , Tez. dokl. VI. Resp. konf. molodykh uchenykh, Vilnius University, 1983 (p. 114) (in Russian).
3. , , , , and , Materialy 4. vses. konf. perestraivaemye po chastote lazerny, Ed. , Inst. Teplofiz., Novosibirsk 1984 (p. 78).