Instruction:
The available Boolean operators are:
Boolean and Syntax
- If Boolean operators are not entered, NLM Image Database assumes it is one long term.
- NLM Image Database processes all Boolean connectors in a left-to-right sequence. You can change the order that the Database processes a search statement by enclosing concepts in parentheses. The terms inside the set of parentheses will be processed as a unit and then incorporated into the overall strategy.
Example: bone marrow AND (Reed-Sternberg OR lymphocyte)