In both simple and advanced search, you can use the Boolean operators AND, OR, and NOT. These must be written in capital letters.

AND
If no operator is specified, search terms are automatically combined using AND. This means that all search terms must appear in the results. Note that the terms may appear in the table of contents and not necessarily in the bibliographic record.

OR
At least one of the search terms connected with OR must appear in the results. OR is typically used to combine related terms in order to broaden the search (e.g. synonyms or different spellings):

NOT

The search term following NOT must not appear in the results. In other words, NOT allows you to explicitly exclude words or phrases from your search.