1. Alfimenkov, V.P., Borzakov, S.B., Vezhbitskij, Y., Ovchinnikov, O.N., Pikelner, L.B., Sharapov, E.I.: 1979, Russ. J. Exp. Theor. Phys. (Lett.) 29(1), 100 (in Russian).
2. Avrett, C.W.: 1981, In: Cram, L.E., Thomas, J.H. (eds.) The Physics of the Sunspots, AURA, Sacramento Peak Observatory, Sunspot, 235.
3. Babin, A.N., Koval, A.N.: 1999, Kinematika Fiz. Nebesnykh Tel (Kiev) 15, 51 (in Russian).
4. Baranovskij, E.A.: 1989, In: Somov, B.V. (ed.) Investigations of Solar Plasma, Ashkhabad, Ylym, 228 (in Russian).
5. Boiko, A.Y., Livshits, M.A.: 1995, Russ. Astron. Rep. 72, 381.