1. P. Gessini, M. Coletti, N. Bevan, R. Intini Marques, G. Michalareas, S.B. Gabriel, Solar electric propulsion for lunar transfer, Solicited paper, in: First Hellenic-European Student Space Science and Technology Symposium, Patras, Greece, October 2006.
2. P. Gessini, S.B. Gabriel, D.G. Fearn, A study of the thrust generated by a t6 hollow cathode, AIAA Paper 2006-5265, 42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Sacramento, CA, July 2006.
3. P. Gessini, S.B. Gabriel, D.G. Fearn, Thrust characterization of a T6 hollow cathode, IEPC Paper 05-257, 29th International Electric Propulsion Conference, Princeton, NJ, October–November 2005.
4. A.N. Grubisic, S.B. Gabriel, Application of hollow cathodes as a plasma propulsion device, in: 46th AIAA Aerospace Sciences Meeting and Exhibit Reno, Nevada, January 2008.
5. A.N. Grubisic, S.B. Gabriel, D.G. Fearn, Hollow cathode thrusters for all-electric spacecraft, IAC-07-C4.4.07, in: 58th International Astronautical Federation Congress, Hyderabad, India, September 2007.