[Reports] / Amer.inst.of aeronautics and astronautics. N 89-2381 : State-of-the-art of radio-frequency ion thrusters : Rep. presented at the AIAA/ASME/SAE/ASEE 25th joint propulsion conf.,Monterey(Ca)/July 10-12,1989 / K.H.Groh,H.W.Loeb, 1989. - 12 p. - Текст : непосредственный.