1. Weber, R J and Pauson, W M , "Some thrust and trajectory considerations for Iunar landings," NASA TN D-134 (1959)
2. April 1962;Mason M
3. Hakes, R C , "Guidance and navigation systems for Iunar missions," ARS Preprint 2294-61 (1961)
4. Queijo, M J , Miller, Jr, and Kimball, G , "Analysis of two thrusting techniques for soft Iunar landings starting from a 50-mile altitude circular orbit," NASA TN D-1230 (1962)