Try these resources first when beginning your research. This list will assist you with your class assignments, including study of the Mike Mansfield objects in Archives and Special Collections.
Oxford Art Online
You will need your NetID and password to access this from off-campus. Limited to 3 concurrent users; if you can't get into the database on the first try, then please check back later.
If you're looking for articles related to art or art history, here is a list of databases to help you get started: