1. Boelee, A.: 1981, internal report, Laboratory for Space Research, Utrecht.
2. Hildner, E. and 19 co-authors: 1985, in M. Kundu and B. E. Woodgate (eds.), SMM Workshop Proceedings, Chapter 6, in press.
3. McCabe, M., Švestka, Z., Howard, R., Jackson, B., and Sheeley, N. R.: 1986, Solar Phys., in press.
4. Mewe, R., Gronenschild, E. H. B. M., and Van den Oord, G. H. J.: 1985, Astron. Astrophys. Suppl. 62, 197.
5. Schadee, A., De Jager, C., and Svestka, Z.: 1983, Solar Phys. 89, 287.