1. Brasseur, G. and Simon, P. C.: 1981, J. Geophys. Res. 86, 7343.
2. Finkenzeller, U. and Labs, D.: 1979, Appl. Opt. 18, 3938.
3. Hardorp, J.: 1980, Astron. Astrophys. 91, 221.
4. Hardorp, J., Caldwell, J., and Wagener, R.: 1982, Advances in Ultraviolet Astronomy, NASA, Greenbelt.
5. Heath, D. F.: 1980, Proceedings of International Conference on Sun and Climate, Centre National d'Etudes Spatiales, p. 163.