1. V. I. Tsaryuk, V. D. Savchenko, and V. F. Zolin, Zh. Prikl. Spektrosk.,56, No. 2, 183–191 (1992).
2. M. A. Porai-Koshits, L. A. Aslanov, and E. F. Korytnyi, Itogi Nauki i Tekhniki, Ser. Kristallokhimiya [in Russian], VINITI, Moscow,11, 5–94 (1976).
3. N. V. Starostin and S. A. Titov, Opt. Spektrosk.,37, No. 2, 276–278 (1974).
4. M. I. Gaiduk, V. F. Zolin, V. A. Kudryashova, and V. I. Tsaryuk, Izv. Akad. Nauk SSSR, Ser. Fiz.,32, No. 9, 1555–1559 (1968).
5. V. I. Tsaryuk, Author's Abstarct of Candidate's Dissertation in the Physical-Mathematical Sciences, Moscow (1978).