In some of the ProQuest databases, you will see a Thesaurus option above the search boxes. Searching for the thesaurus term for a topic will retrieve papers on that topic even if different authors have used slightly different terminology to describe the topic in their papers.
If you click on Thesaurus you will see a list of relevant thesauri, depending on which database you are in. For example MeSH for Medical Subject Headings or ERIC for education-related terms.
To add Thesaurus terms to your search:
Your selected terms will be added to the search box on the Advanced Search screen. You can now either just search or combine with other terms and use the limiters available on this screen.