Examples: |
Results: |
| birth defect* |
retrieval set includes coverage of birth defect or birth
defects |
| birth defects and folic acid |
retrieval set includes content covering birth defects and folic
acid in the same document |
| birth defects or folic acid |
retrieval set includes either content covering birth defects or
content covering folic acid |
| birth defects not folic acid |
retrieval set includes content that covers birth defects where folic
acid is not covered in the document |
| (neural tube defects or birth defects) and folic acid |
retrieval set includes content where either neural tube
defects or birth defects is covered and prevention
with folic acid is covered in all content |
| "neural tube" |
retrieval set includes content where the exact phrase neural
tube appears in the document |
