1. Hugh L. Dryden, Ph.D., “Footprints on the Moon”, National Geographic Magazine, Vol. 125, No. 3, March 1964.
2. Dr. C.S. Draper, H.P. Whitaker, and L.R. Young, “The Roles of Men and Instruments in Control and Guidance Systems for Spacecraft,” to be published in the Proceedings of the 15th International Astronautical Congress, Warsaw, 1964.
3. J.M. Dahlen and J.L. Nevins, “Navigation for the Apollo Program,” MIT Instrumentation Laboratory Report, R-447, May 1964, given at the National Space Meeting, St. Petersburg, Florida, April 30, 1964.
4. M. Kramer, “Apollo Command Module and LEM Guidance Navigation Systems,” published in Apollo-A Program Review, SP 257, Society of Automotive Engineers, Inc., 1965.
5. Unpublished MIT Paper by David G. Hoag.