1. G. A. Galazutdinov, Stellar Echelle Spectrum Processing System (Nizhnii Arkhyz, 1992), Preprint No. 92 (Special Astrophysical Observatory, Russian Academy of Sciences).
2. Y. M. Maharramov, “Unusual Variations in the Atmosphere of the Star 55 Cyg,” Azerb. Astron. J. 5(3), 23–28 (2010).
3. Kh. M. Mikailov, V. M. Khalilov, and I. A. Alekberov, “Cassegrain Echelle Spectrometer of the 2-m Telescope of ShAO NAS Azerbaijan,” Tsirk. Shamakhy. Astrophys. Obs., No. 109, 21-29 (2005).
4. V. V. Sobolev, Moving Envelopes of Stars (Sci., Moscow, 1947).
5. V. V. Sobolev, Course in Theoretical Astrophysics (Sci., Moscow, 1985).