Books (digital or print) are excellent sources of IN-DEPTH background information. Don't think of these books as cover to cover novels you need to read all of- often it's one chapter or section that is useful for your topic. But what they do offer is a unique type of information that will be helpful for your research.
CT State Northwestern Quick Search: (Catalog + E-Resources)
Still Can’t Find What You Need? Try the Library’s Interlibrary Loan service: