From: NLM Catalog
NLM Catalog Help [Internet].
Bethesda (MD): National Center for Biotechnology Information (US); 2007-.
NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.
Examples: |
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common cold AND (vitamin C OR zinc) |
heart disease AND (aspirin OR dilantin) |
From: NLM Catalog
NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.