1. On the motion of satellites with critical inclination Publication/Creation: Washington : Smithsonian Institution, 1961 Resource Type: Book Access & Availability: Loading
2. Orbital data and preliminary analyses of Satellites 1957 Alpha and 1957 Beta Author/Creator: Whipple, Fred L. 1906-2004. (Fred Lawrence) Publication/Creation: Washington : Smithsonian Institution, 1958 Resource Type: Book Access & Availability: Loading