As you learn more about your topic and start to find some relevant sources, you'll get a better idea of what you still need to find.
There are some strategies you can use to do a more targeted search, which is sometimes called "refining" your search.
Check out the strategies below.
If you've only searched one or two databases, try searching another! Often, different databases include different articles. Look at the list of databases on the first page of this guide for ideas.
Once you've found one or more sources that relate to your topic, pay attention to the language the authors use. Look for relevant words and phrases that you haven't searched yet. It's likely that other scholars writing on the same topic have used similar terms.
Look for new search terms in these places:
Check out this example:
When you've found one paper that's very relevant to your topic, you can follow the references to find other relevant papers.
Look at the article's reference list to see who the authors have cited.
Use Google Scholar or Scopus to see which newer papers have cited this article (usually called "cited by").
Look at the sources you've already found and start to think about how you'll use them in your research paper.
As you start to outline your paper, think about where your sources fit in. Is there anything missing? Are there any topics you want to discuss that you haven't found information about?
When you identify an area that's missing from your research, come up with some words and phrases that relate to this missing area. Try a new search with these terms to see if you can find some sources.