Columbia subject headings:
Mars (Planet)--Exploration--Catalogs.
Viking Mars Program (U.S.)--Catalogs.
Harvard subject headings:
Mars (Planet)--Exploration--Catalogs.
Mars (Planet)--Exploration.
Viking Mars Program (U.S.)--Catalogs.
Viking Mars Program.
Princeton subject headings:
Mars (Planet)--Exploration--Catalogs.
Viking Mars Program (U.S.)--Catalogs.