1. Brandt, P.N., Scharmer, G.B., Ferguson, S., Shine, R.A., Tarbell, T.D., Title, A.M., Submitted to Nature.
2. Dunn, R.B., 1969, Sky Telesc. 38, 368
3. Koutchmy, S., Lebecq, C., 1984, Solar Phys. 93, 243.
4. Mehltretter, J.P.,1979, J. Opt. 10, 93.
5. November, L.J., Toomre, J., Gebbie, K.B., Simon, G.W., 1981, Astrophys. J.
245, L123.