1. Photographic observations often artificial meteors;Ayer;Smithsonian Astrophysical Observatory Report, no. 317,1970
2. Orbits and masses of planets and satellites;Brouwer,1961
3. 2001: A Space Odyssey;Clarke,1968
4. Physics and Dynamics of Meteors;Cook,1968
5. Optical properties of Saturn's rings. I. Transmission;Cook;Smithsonian Contrib. Astrophys.,1958