Google's advanced search allows you to search by domain name (on bottom line of the advanced search form).
Entering .edu or .gov into this line will only return results from educational or US government sites, which tend to contain more reliable scholarly or factual information. You will still have to evaluate the sites for authority, accuracy, currency, and objectivity.
Google Scholar The Google search engine for academic sites including colleges, universities, publishers, and more.
Google Books Most books are available in only snippet or preview mode, but you can sample and decide if the book is worth getting through interlibrary loan.
Google Images A search engine for images. The results you find may have copyright restrictions.