1. Bobrov, M. S.: 1961, ?Generalization of the Theory of the Shadow Effect on Saturn's Rings to the Case of Particles of Unequal Size?,Sov. Astron. AS. 4, 288.
2. Camichel, A.: 1958, ?Mesures Photom�triques de Saturne et de son Anneau?,Ann. Astrophys. 21, 231.
3. Dollfus, A.: 1962, Astrophysics V: Miscellaneous inEncyclopedia of Physics (ed. by S. Flugge)LIV, Springer-Verlag, Berlin, Gottingen, Heidelberg, p. 218.
4. Franklin, F. A. and Cook, A. F.: 1965, ?Optical Properties of Saturn's Rings?,Astron. J. 70, 704.
5. Focas, J. H. and Dollfus, A.: 1969, ?Propri�t�s Optiques et Epaisseur des Anneaus de Saturne Observ�s par la Tranche en 1966?,Astron. Astrophys. 2, 251.