1. Chandrasekhar, S.: 1969, Ellipsoidal Figures of Equilibrium. Yale University Press, New Haven (Conn.)/London.
2. Consolmagno, G. L. and Lewis, J. S.: 1977, in J. A. Burns (ed.), Planetary Satellites, pp. 492?500. University of Arizona Press, Tucson.
3. Davies, M. E. and Katayama, F. J.: 1983, Icarus 53, 332.
4. Dermott, S. F.: 1979, Icarus 37, 575.
5. Farinella, P., Ferrini, F., Milani, A., and Nobili, A. M.: 1981, The Moon and the Planets 24, 465.