1. Baker, N. H. and Temesvary, S.: 1966, Tables of Convective Stellar Envelope Models, 2nd ed., Goddard Institute for Space Studies, N.-Y.
2. Drobyshevski, E. M.: 1971, Solar Data (Pulkovo) No. 6, 84.
3. Durney, B. R.: 1976, Astrophys. J. 204, 589.
4. Gilman, P. A.: 1974, Ann. Rev. Astron. Astrophys. 12, 47.
5. Landau, L. D. and Lifshitz, E. M.: 1959, Fluid Mechanics, Pergamon Press, London.