1. Falk, G., Ruppel, W.: Energie and Entropie, Springer-Verlag, Berlin, Heidelberg, New York 1976
2. Development in Atm. Sciences;H Fortak,1979
3. Ekman, V.W.: Ark. Math., Astron. och Fysik 2, 52 (1965)
4. NATO Advanced Study Inst. Series;J Woods,1981
5. Maxwell, J.C.: A Treatise on Electricity and Magnetism, 2 Vols., Oxford 1873