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PubMed @ UMSL

Step-by-step guide to PubMed's basic and advanced features, with downloadable handouts.

Similar Articles

Citation page navigation showing similar articles


For each citation, PubMed provides a link to Similar articles. By default, it provides five articles, but you can expand the list to Show more or See all.

Similar articles for one citation

The filters you selected for your primary search will be retained when viewing similar articles. Clear the filters to expand the search even further.

Cited By

Citation page navigation showing Cited by link


When the citation you're viewing has been cited by others, you can follow the citation trail to locate other articles on the subject. 

Cited by section for one article

Boolean Operator OR

Three Venn diagrams representing the intersection of heart AND lung, the separation of heart OR lung, and the exclusion of heart NOT lung.


To expand your results using Boolean operators, try adding synonyms/related terms with OR (in capital letters): for example, exercise (anxiety OR depression). The parentheses in this search clarify that you’re looking for articles about exercise that also discuss anxiety or depression. Without the parentheses, PubMed would look for articles about exercise and anxiety OR articles about depression (an extremely broad search). Please speak with a Reference Librarian if you need help combining search terms with Boolean operators.

Additional Tips

  • Look for misspellings in your search terms.
  • Decrease the number of concepts searched.
  • Try a broader search term.
  • Remove terms that are unlikely to be used by an author.
  • Replace terms that are too general or too specific.
  • Increase the number of synonyms or alternatives for a term.
  • Use a truncation symbol at the end of a term to pick up variant endings (see the Basic Search section).
  • Try the same search(es) in different databases.
  • Use a term from the thesaurus (i.e., MeSH or subject heading list) for searching. 
  • Ask for significant words to be in the full text of the article (field searching).
  • Check for missing or incorrect field qualifiers.