1. É. I. Mogilevski, Fractals on the Sun (Fizmatlit, Moscow, 2001) [in Russian].
2. G. B. Field, Astrophys. J. 142, 531 (1965).
3. V. A. Kovalev, Kinemat, Fiz. Nebesn. Tel 6, 381 (1990).
4. A. I. Laptukhov, Interplanetary Medium and Magnetospheric Processes (Nauka, Moscow, 1991) [in Russian].
5. V. A. Kovalev and A. I. Laptukhov, Issled. Zemli Kosm., No. 1, 11 (1992).