Although you should primarily use library databases for your research, there are times when it may be more appropriate to use a document from the web. Because most information on the web has not gone through the extensive review process that books and journal articles do, it is important that you verify that the information you find has come from a reliable source.
One way to do this is to only retrieve articles from U.S. government websites. You can do this by adding site:gov to the end of your Google search.