1. Axford, W.I.: 1972, in C.P. Sonnett, P.J. Coleman Jr., and J.M. Wilcox (eds.), The Solar Wind, NASA SP, 308, 609.
2. Baranov, V.B., Lebedev, M.G., and Malama, Yu. G.: 1991, Astrophys. J., 375, 347.
3. Bertin, P., Lallement, R., Ferlet, R., and Vidal-Madjar, A.: 1993, J. Geophys. Res., 98, 15193.
4. Bleszynski, S.: 1987, Astron. Astrophys., 180, 201.
5. Chassefi�re, E., Bertaux, J.L., Lallement, R., and Kurt, V.G.: 1986, Astron. Astrophys., 160, 229.