Finding the right search terms can be a major challenge. Being attentive to the terminology you find in materials you've already located is important, and then you have to figure out how to combine them. This tool can help.
Different databases have different subject strengths, and using just one or two is a good strategy if you have a fairly broad topic.
Academic Search Complete is a large scholarly, multidisciplinary, full-text database, with more than 7,400 full-text periodicals, including more than 6,300 peer-reviewed journals. In addition to full text, this database offers indexing and abstracts for more than 11,500 scholarly, popular, trade, and special interest serials, and a total of more than 12,000 publications including monographs, reports, conference proceedings, and more. Updated daily.