1. Allen, C. W., 1973, Astrophysical Quantities (3rd Edition), Athlone Press, University of London
2. Cook, A. F., 1973, in Evolutionary and Physical Properties of Meteoroids, IAU Col.13, 183–191, NASA SP319
3. Drummond, Jack D., 1981a, Icarus, 45, 545, 1981
4. Drummond, J. D., 1981b, Icarus, 47, 500
5. Everhart, E., 1972, Astrophysical Lett, 10, 131