•PubMed has a feature called Automatic Term Mapping.

•When you use natural language (like breast cancer treatment) in the basic search, then you can view how the search terms are automatically mapped to various search fields (like author or journal title) and synonyms (including MeSH terms) under the “Details” section of the search history (under Advanced Search).

•Automatic term mapping is helpful for returning broader results, but it can also be useful to know how to create more targeted searches using search fields and combined searches.