1. Altenhoff W., Batrla W., Huchtmeier W., Schmidt J., Stumpf P., Walmsley M., 1983 IAUC Circ 3817, June 1.
2. Brownlee D.E., Rajan R.S., Tomandl D.A., 1977 in ?Comets, Asteroids, Meteorites? p 137, ed. Delsemme, Publ. U. of Toledo Bookstore.
3. Cameron A.G.W., 1978, Moon and Planets18, 5.
4. Cameron A.G.W., 1979, Moon and Planets21, 173.
5. Chamberlain, J.W., 1978, Theory of Planet. Atmos., publ. Academic Press, New York.