1. Bandiera, R.: 1982, Astron. Astrophys. 112, 52.
2. Cohen, M. H.: 1960, Astrophys. J. 131, 664.
3. Gelfreikh, G. B.: 1981, in A. E. Balklavs (ed.), Dynamics of Current Sheets and Physics of Solar Activity, Zinatne Publ., Riga, p. 116.
4. Kakinuma, T.: 1958, Proc. Res. Inst. Atmos. Nagoya Univ. 5, 1, 71.
5. Kravtsov, Yu. A. and Naida, O. N.: 1976, Zh. Experim. Teor. Fiz. 71, No. 7, 237.