1. A survey of existing satellites in resonant orbits for geodetic purposes;Wagner;NASA-GSFC-X-643-68-256,1968
2. Theory of Satellite Geodesy;Kaula,1966
3. The motion of a close Earth satellite;Kozai;Astr. J.,1959
4. The Earth's gravitational field as derived from a combination of satellite data with gravity anomalies;Köhnlein,1967
5. Table of the Earth satellites;King-Hele;Planet. Space Sci.,1963