1. The origin of meteorites as small bodies;Arnold;Astrophys. J.,1965
2. Early lunar cratering;Hartmann;Icarus,1966
3. Lunar crater counts. VI. The young crater Tycho, Aristarchus, and Copernicus;Hartmann;Comm. Lunar Plan. Lab.,1968
4. Preliminary note on lunar cratering rates and absolute time-scales;Hartmann;Icarus,1970
5. On the origin of the lunar surface features;Kuiper,1954