1. Propulsion system tradeoff studies for geosynchronous satellites
2. Farrow,J. B. Henn. J. and Wells, A. A. "Electric Propulsion Systems for Station-Keeping of EuropeanCommunicationsSatellites,"pp. 181 - 186. 4. Lechte. H. G. and van Holtz. L. C. "The Role of Elecnic Propulsion in Extending the Economic LifeCycle of Commercial European Telecommunications Satellites." IEPC-88-007.
3. 20th mc, DGLR-Bericht 88-02, Garmisch-Partenkirchen. Germany, pp. 58-61, October 1988.