1. M. J. Aschwanden, Particle Acceleration and Kinematics in Solar Flares (Kluwer Academ. Publ., Dordrecht, 2002).
2. S. A. Bogachev and B. V. Somov, Astron. Zh. 78, 187 (2001) [Astron. Rep. 45, 157 (2001)].
3. S. A. Bogachev and B. V. Somov, Pis’ma Astron. Zh. 31, 601 (2005) [Astron. Lett. 31, 537 (2005)].
4. S. A. Bogachev and B. V. Somov, Pis’ma Astron. Zh. 33, 62 (2007) [Astron. Lett. 33, 54 (2007)].
5. J. C. Brown and P. Hoyng, Astrophys. J. 200, 734 (1975).