The National union catalog, pre-1956 imprints ;
a cumulative author list representing Library of Congress printed cards and titles reported by other American libraries /
Compiled and edited with the cooperation of the Library of Congress and the National Union Catalog Subcommittee of the Resources Committee of the Resources and Technical Services Division, American Library Association.
APA Citation
American Library Association. Committee on Resources of American Libraries. National Union Catalog Subcommittee., Library of Congress. (19681981). The National union catalog, pre-1956 imprints: a cumulative author list representing Library of Congress printed cards and titles reported by other American libraries. London: Mansell.
MLA Citation
American Library Association. Committee on Resources of American Libraries. National Union Catalog Subcommittee, and Library of Congress. The National Union Catalog, Pre-1956 Imprints: a Cumulative Author List Representing Library of Congress Printed Cards And Titles Reported by Other American Libraries. London: Mansell, 19681981.
Warning: These citations may not always be complete (especially for serials).