1. Alexander, A. F. The Planet Saturn (Faber and Faber, London, 1962).
2. Sanchez-Lavega, A. Icarus 44, 1–16 (1982).
3. Sanchez-Lavega, A. & Battaner, E. Astr. Astrophys. Suppl. Ser. 64, 287–301 (1986).
4. Tomasko, M. G., West, R. A., Orton, G. S. & Tejfel, V. G. in Saturn (eds Gehrels, T. & Matthews, M. S.) 150–194 (University of Arizona Press, Tucson, 1984).
5. Smith, B. A. et al. Science 212, 163–191 (1981).