APA
Library of Congress, Library of Congress, . (1970). National Union Catalog, 1969. Washington: Library of Congress.
Chicago
Library of Congress, Library of Congress, . 1970. National Union Catalog, 1969. Washington: Library of Congress.
Harvard
Library of Congress, Library of Congress, . (1970). National Union Catalog, 1969. Washington: Library of Congress.
MLA
Library of Congress, Library of Congress, . National Union Catalog, 1969. Washington: Library of Congress. 1970.
