1. “Electrical propulsion in space: mission comparisons, development cost, reliability, and the implications for planning,”;Pinkel,1964
2. “Nuclear electric spacecraft for unmanned planetary and interplanetary missions,”;Spencer,1962
3. Research on spacecraft and powerplant integration problems,”,1963
4. “Interplanetary trajectories and payload capabilities of advanced propulsion vehicles,”;Melbourne,1961
5. “Interplanetary operations,”;Ehricke,1959