1. A. G. Nikoghossian, Astrofizika 54, 617 (2011) (N1).
2. A. G. Nikoghossian, Astron. Astrophys. 422, 1059 (2004).
3. S. Chandrasekhar, Radiative Energy Transfer [Russian translation], IL, Moscow (1953).
4. V. V. Sobolev, Radiative Transfer in the Atmospheres of Stars and Planets [in Russian], Gostekhizdat, Moscow (1956).
5. R. G. Athay, Radiation Transport in Spectral Lines, D. Reidel, Dordrecht (1972).