sponsored by National Aeronautics and Space Administration ... [and others] ; held at Lyndon B. Johnson Space Center, Houston, Texas, September 23-25, 1980
sponsored by the National Aeronautics and Space Administration, Washgington, D.C., and hosted by the University of Houston-Clear Lake, Houston, Texas, and held at NASA Lyndon B. Johnson Space Center, Houston, Texas, April 12-14, 1989 ; Sandy Griffin, editor