| 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. London : Mansell, 1968-1981. 754 v. |
| This is a catalogue of the books and journals published before 1956 that are found in hundreds of U.S. Libraries. |
| Since this merges the holdings of many of the best research libraries in the world, it is an excellent source of bibliographic information on publications of historical interest. |
