jointly sponsored by the American Astronomical Society, Washington, D.C., and the NASA Lyndon B. Johnson Space Center, Houston, Texas, and held in Houston, Texas, January 10, 1986 ; edited by Jack O. Burns, Wendell W. Mendell
sponsored by the National Aeronautics and Space Administration, the University of New Mexico, and the BDM Corporation, and held at the BDM Corporation, February 18-19, 1988 ; edited by Jack O. Burns ... [and others]