Worldcat (a.k.a.OCLC). (Online)
Comprehensive database that serves as a major union catalog of records held in libraries around the world, including many major research and academic libraries; archives and museum libraries; law, medical, and theological libraries; art and music libraries; area studies collections; public and corporate libraries; historical societies and book clubs. Entries describe books, serials, archival collections, manuscripts, maps, music scores, sound recordings, films, photographs, posters, electronic resources, and more. The Catalog extends from the advent of printing to the present. New records are added daily.
Arcade / New York Art Resources Consortium. (Online)
Merged library catalogs of the Museum of Modern Art Library, the Frick Art Reference Library and the Brooklyn Museum of Art Libraries and Archives.
Harvard University Libraries (a.k.a. HOLLIS). (Online)
Includes Fine Arts Library, Graduate School of Design, Villa I Tatti, Florence. Berenson Library, and more.
Metropolitan Museum of Art Library. (New York, N.Y.) (a.k.a. Watsonline). (Online)
Part union catalog and part index; it contains the holdings of the nine libraries of the German Archaeological Institute (head office in Berlin; Eurasia Department, Orient Department, Commission for Archaeology of Non-European Cultures (KAAK) in Bonn; with departments in Rome, Madrid, Athens, Istanbul, and Cairo) and it also contains records for journal articles, conference proceedings, book chapters, and Festschriften. The bibliography covers Greek and Roman culture and its peripheral culture, as well as the literature on Etruscan, Minoan, and Mycenaean culture; the Anatolian cultures; and prehistory and ancient history including epigraphy and numismatics.