1. 3Seikel, G. R. "Generation of Thrust - Electromagnetic Thrusters," Proceedings of the NASA-University Conference on the Science and Technology of Space Exploration, Vol.2, Nov. 1962, pp.171-176.
2. 4Ellis,M.C."SurveyofPlasmaAccelerationResearch,"ProceedingsoftheNASA-UniversityConferenceontheScienceand Technology of SpaceExploration, Vol. 2,Nov. 1962, pp.373-375.