1. Elste, G.: 1988, in P. Foukal (ed.), Solar Radiative Output Variation, available from CRI, Inc., Cambridge, U.S.A., p. 204.
2. Kuhn, J.: 1988, in P. Foukal (ed.), Solar Radiative Output Variation, available from CRI, Inc., Cambridge, U.S.A., p. 217.
3. Neckel, H. and Labs, D.: 1987a, Solar Phys. 110, 139.
4. Neckel, H. and Labs, D.: 1987b, Solar Phys. 110, 201.
5. Petro, L., Foukal, P., and Kurucz, R.: 1985, Solar Phys. 98, 23.