Trajectories of artificial celestial bodies, as determined from observations : Proceedings of a symposium held in Paris, April 20-23, 1965 / Kovalevsky, Jean, Kovalevsky, Jean, ed. COSPAR. Space trajectories Congresses. Astrodynamics Congresses. TL1075 .K65 521.6 KOT At head of title: COSPAR-IAU-IUTAM. Includes bibliographical references and index New York, Springer-Verlag, 1966. 1966. 1966 Text xvi, 265 p. : eng engfre