1. Carter, C. S., Snodgrass, H. B., and Bryja, C.: 1992,Solar Phys. 139, 13.
2. Dezsö, L. and Kovács, Á.: 1994, in W. Schmidt and M. Schüssler (eds.),Solar Magnetic Fields, Cambridge University Press, Cambridge (in press).
3. Dezsö, L., Gerlei, O., and Kovács, Á.: 1987, ?Debrecen Photoheliographic Results for the Year 1977?,Publ. Debrecen Obs. Heliogr. Ser., No. 1.
4. Dezsö, L., Gerlei, O., and Kovács, Á.: 1993, ?Debrecen Photoheliographic Results for the Year 1978?,Publ. Debrecen Obs. Heliogr. Ser., No. 2 (not yet published).
5. Howard, R., Gilman, P. A., and Gilman, P. I.: 1984,Astrophys. J. 283, 373.