Gingrich Library: Your Success Is Why We're Here!
Google's advanced search allows you to search by domain name (on bottom line of the advanced search form).
Entering .edu, .gov or .org into this line will only return results from educational, organizational or US government sites. You will still have to evaluate the sites for authority, accuracy, currency, and objectivity.
Google Scholar eliminates the commercial parts of Google and points to more scholarly information.
Use critical thinking skills and evaluate the websites you find.