1. B. E. Markaryan and V. A. Lipovetskii, Astrofizika,9, 487 (1973);10, 307 (1974);12, 389, 657 (1976).
2. B. E. Markaryan, V. A. Lipovetskii, and Dzh. A. Stepanyan, Astrofizika,13, 225, 397 1977);15, 201, 363, 549 (1979).
3. V. A. Sanamyan and R. A. Kandalyan, Astrofizika,14, 625 (1978);15, 701, (1979).
4. G. Kojoyan, R. Elliot, and H. M. Tovmassian, Astron. J.,83, 1445 (1978).
5. G. M. Tovmasyna, É. Ts. Shakhbazyan, and R. A. Kandalyan, Soobshch. Byurak. Obs. Akad. Nauk Arm. SSSR,52, (1979) (in press).