1. Darvann, T. A.: 1992, in Z. Yi, T. Darvann, and R. Molowny-Horas (eds.),Proc. from LEST Mini-Workshop, LEST Technical Report No. 56, pp. 91.
2. Ewell, M. W.: 1992,Solar Phys. 137, 215.
3. Johannesson, A.: 1992, Ph.D. Thesis, University of Lund.
4. Kitai, R.: 1986,Solar Phys. 104, 287.
5. Lites, B. W., Scharmer, G. B., and Skumanich, A.: 1990,Astrophys. J. 355, 329.