1. "Catalog" tab to the Duke Libraries catalog
Example:
1. Key words (i.e., natural language) REPETION ART
2. select the first book that appears (even just generally) to be on your topic
3. Book: On Repetition, Writing, Performance
4. Use the subject headings assigned to the book to find like topics REPETION (ESTHETICS)
2. Google Books & Google Scholar
Google Books allows you to search books by key-word. It does not display the whole book. Use LIBX.
Google Scholar is the same but for articles.
Worldcat - combined catalog of all libraries
Use Worldcat to locate exhibition catalogs and books for interlibrary loan and archives of collections. There's a "libraries with this item" link that shows NC libraries first.
Virtual Catalogue for Art History (www.artlibraries.net) - consortial catalog of the large specialty art libraries (mostly art museums libraries), including Met, MoMA, and major foreign institutions. Helpful because subject is only art(s); interlibrary-loan is not possible, but this catalog confirms the existence of items possibly obtainable through other methods.
Arcade - The collections of the Frick Art Reference Library, the Brooklyn Museum Library and The Museum of Modern Art Library.
https://archive.org/details/metmuseumlibraries