1. J. F. Wasserbauer; AIAA-Paper 63–029, 1963.
2. M. P. Ernstene, A. T. Forrester, C. R. Speiser, R. M. Worlock; „Progress in Astronautics and Rocketry“, New York: Academic Press 1961, 5, 163.
3. F. G. MacGuire; Missiles a. Rockets 8, 25, 1961.
4. M. P. Ernstene et al.; J. Spacecraft a. Rocketry 3, 744, 1966.
5. E. Stuhlinger; 3rd SES Meeting Davie Camp 1965.