1. Andretta, V., Jones, H.P.: 1997, Astrophys. J. 489, 375.
2. Benevolenskaya, E.E., Kosovichev, A.G., Scherrer, P.H.: 2001, Astrophys. J. 554, L107.
3. Bevington, P.R., Robinson, D.K.: 1992, Data Reduction and Error Analysis for the Physical Sciences, 2nd edn., McGraw-Hill, New York, 62.
4. Beyer, W.H. (ed.): 1991, CRC Standard Mathematical Tables and Formulae, 29th edn., CRC Press, Boston, 175.
5. Bohlin, J.D.: 1977, In: Zirker, J.B. (ed.) Coronal Holes and High Speed Wind Streams, Colorado Associate University Press, Boulder, 27.