Não informado. (1977). NASA Conference Publication. National Aeronautics and Space Administration.
Chicago-referens (17:e uppl.)Não informado. NASA Conference Publication. Washington: National Aeronautics and Space Administration, 1977.
MLA-referens (8:e uppl.)Não informado. NASA Conference Publication. National Aeronautics and Space Administration, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.