AND NOT Connector
Use the AND NOT connector to find documents in which a search word or phrase is to be excluded.
For example, the following search finds documents where the phrase "martin johnson" occurs but neither the words "rugby" nor "sport" occur.
martin johnson AND NOT (rugby OR sport)
Because the exclusion covers the entire document, a document would be excluded if the words "rugby" or "sport" appear anywhere in the document.
Putting AND NOT last
If you include AND NOT in your search, it should be the last connector you use. Otherwise it may produce undesired results.