1. AAS/AIAA Astrodynamics Conference;Bourke,1970
2. Paper presented at the AAS National Meeting;Eckman,1969
3. Study of a 1973 Venus/Mercury Mission with a Venus Entry Probe, Document 760-1 (JPL internal document);Jet Propulsion Laboratory,1967
4. The Determination and Characteristics of Ballistic Interplanetary Trajectories Under the Influence of Multiple Planetary Attractions, Technical Report 32–464;Minovitch,1963