Worldcat. Columbus, Ohio: OCLC. Union list of books and other materials in libraries worldwide.

Artbibliographies modern.  Oxford: CLIO, 1969-  Excellent for late nineteenth and early twentieth century subjects.  Best single source for photography references.  Indexes books, articles, dissertations, exhibition reviews, and other material.

Avery Index to Architectural Periodicals. Santa Monica: Getty Trust, 1979 - Offers a comprehensive listing of journal articles published worldwide on architecture and design, archaeology, city planning, interior design, and historic preservation.

Art Index Retrospective and Art Abstracts. New York: W. Wilson Col. Basic index to primarily English language art periodicals and museum bulletins. Coverage is comprehensive, with entries listed under author and subject. Good source for exhibition and book reviews. Reproductions of works of art listed separately under artist's name. Material indexed between 1929 and 1984 covered by Art Index Retrospective; later material covered by Art Abstracts

Historical Abstracts . 1964- Abstracts of articles, books, dissertations, etc. on historical subjects after 1450. Do not use with IE on a Macintosh

America: History and Life.  ABC-Clio, 1989-  contains citations to articles on the history of the US and Canada from prehistory to the present. Covers over 20,000 journals worldwide.  

Gallica.  Bibliothèque Nationale de France.  Extensive listings of library holdings, including books, maps, posters, image files, newspapers, broadsides, in French collections.