Google Arts & Culture, a Google project
Archives of American Art, Smithsonian Institute (see Research Collections)
Google Images, a search engine for online images
Museums, complied by the University of Michigan (full list of museums)
Norton Simon Museum of Art, Pasadena, California
Los Angeles County Museum of Art, Los Angeles, California
Metropolitan Museum of Art Collections Database
Catalog of Illuminated Manuscripts, British Library
JURN, Humanities Journal Online (open access)
Turabian Quick Guide, University of Chicago
How to Cite Sources in Turabian Format, APU LibGuide
Online Writing Lab, (OWL), Purdue University
Zotero, Free, Firefox extension to help you manage your citations