4. Using Quotation Marks

Quotes are rarely necessary in PubMed: Click Clear to remove the previous search. Then type "heart attack" in the search box, this time surrounded by quotation marks. Click Search and then check the Search Details to see what happened.

Using quotes turns off the automatic term mapping. You are now only searching for the phrase heart attack, and not the MeSH term myocardial infarction or synonyms.

In PubMed, use quotes only if you are having trouble finding an exact phrase.