Adams Library subscribes to several dozen major reference works published by Oxford University Press, accessible through a portal called Oxford Reference Online (ORO).
Once you have entered a search in ORO, use the boxes under AVAILABILITY (left-hand frame) to select “Unlocked” which limits to sources to which Adams Library subscribes. The material under “Free” may also be useful, but examine the subscribed resources first.
Credo Reference provides an online reference collection of over 600+ reference books. This collection includes a variety of dictionaries and encyclopedias, as well as a broad range of subject-specific titles covering everything from art to geography and law to technology.
American National Biography offers portraits of men & women from all eras and walks of life whose lives have shaped the nation. Published in 24 volumes in 1999, the ANB essays, created by scholars chosen for their topical expertise, are updated semi-annually online, with hundreds of new entries each year and revisions of previously published entries to enhance their accuracy and currency. The ANB Online features thousands of illustrations, hyperlinked cross-references, links to select web sites, and powerful search capabilities.
The Oxford DNB is a collection of over 56,000 specially written biographies of men and women who have shaped all aspects of the British past. Updated three time per year with new material published every January, May and October. LIMITED TO 1 USER AT A TIME.
The editors of The Chicago Manual of Style provide a website to support use of their style guide. Although the actual text of the manual online can be seen only by subscribers, a Chicago-Style Citation Quick Guide on constructing some of the most often used types of citations is provided for free.
Purdue University's Online Writing Lab [OWL] makes a more detailed guide to Chicago style available on their website.
Since the Rhode Island College History Department uses the Chicago bibliographic citation style in a modified way, the final arbiter of correct usage is your professor.
The Chicago Manual of Style was not created to support the needs of historians specifically. And so, though it is hundreds of pages long, there are still some unusual items, especially primary sources, which Chicago may not address thoroughly or at all. Consider consulting Evidence explained : citing history sources from artifacts to cyberspace by Elizabeth Shown Mills in the Adams Library Reference Collection: Ref D5 .M55 2007 for examples of sources such as cemetery records, voter rolls, deeds, etc.