Book catalogs and lists which have been incorporated in the Union catalog.
APA Citation
Library of Congress. Union Catalog Division. (1933). Book catalogs and lists which have been incorporated in the Union catalog. Washington: U. S. Govt. prnt. off.
MLA Citation
Library of Congress. Union Catalog Division. Book Catalogs And Lists Which Have Been Incorporated In the Union Catalog. Washington: U. S. Govt. prnt. off, 1933.
Warning: These citations may not always be complete (especially for serials).