The OLDMEDLINE subset in PubMed® represents journal article citations from two print indexes: Cumulated Index Medicus (CIM) and the Current List of Medical Literature (CLML). Created by the National Library of Medicine® (NLM®), there are approximately 2,011,000 article citations from international biomedical journals that cover the fields of medicine, preclinical sciences and allied health sciences from 1946 through 1965. OLDMEDLINE records, which are included in the MEDLINE® database, can be searched via PubMed. The OLDMEDLINE subset in PubMed contains citations from the 1960 through 1965 Cumulated Index Medicus (CIM) print indexes and the 1946 through 1959 Current List of Medical Literature (CLML) print indexes. The OLDMEDLINE subset does not include citations from the Quarterly Cumulative Index Medicus (QCIM) print indexes. A hand search of the QCIM print indexes is necessary to ensure comprehensive review of medical periodical literature of the world from 1946 through 1956.