1. Chamberlain, J. W., and Kuiper, G. P., Astrophys. J., 124, 399 (1956).
2. Moroz, V. I., Physics of Planets (Nauka Press, Moscow, 1967) (NASA Technical Translation F-515, Washington DC, 1968).
3. Carpenter, R. L., Astron. J., 71, 142 (1966).
4. Evans, J. V., and Hagfors, T., Radar Astronomy (McGraw-Hill Book Company, 1968).
5. Vinogradow, A. P., Surkow, Yu. A., and Andreychikow, B. M., Doklady Akademii Nauk SSSR, 190, 552 (1970).