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Boolean Operators AND, OR, NOT

In the Simple Search several search terms are automatically linked with AND. For a more targeted search it is recommended to combine several search terms with each other using Boolean operators.

AND: All entered search terms must occur in the document.

OR: Only one of the entered search terms must occur in the document. This function extends the search area and is useful if different terms exist for a topic.

car OR automobile

NOT: This function has an exclusionary effect and can be used to limit the number of hits: In documents in which one search term occurs, the other must not occur.

golf NOT volkswagen

The Boolean operators also work for the Advanced Search. There they can be used to combine different search terms within a search field. For example, the following search query returns all documents of the author "Mustermann" for the years 2002 or 2003:

Author: Mustermann
Year: 2002 OR 2003


If you're not sure how to spell a search term, such as a name, or if you want to expand your search, you can use * and ? as wildcards. It is not possible to use them at the beginning of a search term.

Example 1: librar* finds library or also librarian.
Example 2: Ma?er finds Mager and Maler.

You can use double quotation marks (") to perform a phrase search.