From: PubMed Help
PubMed Help [Internet].
Bethesda (MD): National Center for Biotechnology Information (US); 2005-.
NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.
| Examples |
|---|
| #2 AND #6 |
| #3 AND (drug therapy OR diet therapy) |
| #5 gene therapy |