1. A. A. Bocharov, Astron. Zh.,64, 1004 (1987).
2. A. A. Bocharov, Izv. Vyssh. Ucheb. Zaved. Radiofiz. (1988) (in press).
3. I. P. Williamson, Mon. Not. R. Astron. Soc.,157, 55 (1972).
4. I. P. Williamson, Proc. R. Soc. London, Ser. A:342, 131 (1975).
5. B. J. Uscinski, The Elements of Wave Propagation in Random Media, McGraw-Hill, New York (1977).