1. Abramowicz, M., Stegun, I. A. 1972,Hand book of Mathematical Functions, Dover, New York.
2. Barbosa, D. D. 1982,Astrophys. J.,254, 301.
3. Bhat, C. L., Kifune, T., Wolfendale, A. W. 1986,Astr. Astrophys.,159, 299.
4. Bloemen, J. B. G. M. 1985,Astr. Astrophys.,145, 391.
5. Chandrasekhar, S. 1960,Radiative Transfer, Dover, New York.