1. Abrams, W. J.: 1966, ?An Investigation of Schroeter's Rule?, Astron. Contr. Boston University, Ser. II, #42.
2. Baldwin, R. B.: 1949, The Face of the Moon, Univ. of Chicago Press, Chicago.
3. Baldwin, R. B.: 1963, The Measure of the Moon, Univ. of Chicago Press, Chicago.
4. Baldwin, R. B.: 1968, ?Rille Pattern in the Lunar Crater Humboldt?, J. Geophys. Res. 73, 3227?3229.
5. Burt, J., Veverka, J., and Cook, K. 1976: ?Depth-Diameter Relation for Large Martian Craters Determined from Mariner 9 UVS Altimetry?, Icarus 29, 83?90.