1. J. R. Oliver and W. M. McCombs, “Lunar Storage of Small Quantities of Cryogenic Fluid,” Report No. TR-4–42–2-D, Kennedy Space Center, Future Studies Branch (January 21, 1964).
2. J. B. Romero, “Propellant Tank Thermal Analysis with Lunar Storage of Cryogens as Examples,” Boeing Document D2–90673–1 (January 28, 1965).
3. D. B. Mackay, Design of Space Power Plants, Prentice Hall, Inc., Englewood Cliffs, N.J. (1963), p. 2.
4. J. M. Saari and R. W. Shorthill, “Isotherms of Crater Regions on Illuminated and Eclipsed Moon,” Icarus 2:115 (1963).
5. E. Kehat, B. A. Buffham, P. M. Silverberg, and R. G. Clark, “Analysis of Cryogenic Feed Systems for Electrothermal Engines,” Air Products and Chemicals, Inc., Summary Report, Project No. 03–1–4290 (October 1961).