If you're working on a topic with which you're not very familiar, it's a very good idea to do some background reading in reference books. You can learn the names of artists and artistic movements and read in detail about their importance. You may encounter terms and topics along the way that will assist your work.
CREDO Reference . . . is a very useful tool to do background reading and develop some perspective on your topic. It contains the full-text of hundreds of general and specialized reference books, such as dictionaries and encyclopedias. Articles will contain references to books and journal articles that may be useful to you.
Like most other online research services, you can easily search for phrases using double quotes, for example, "graphic design" This search form opens Credo with reference books on Art preselected, some of which are generic and some are very specialized. You can also find a huge number of images from the Bridgeman Art Library Archive.