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CAB Direct Help v1.0

Navigation: Keyword Searching

Boolean Operators

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To make searching more accurate you can use Boolean operators (AND, OR, NOT) to link your search terms.


By default, phrases and single words  are searched in combination and are linked with the Boolean operator AND


The search phrase "cattle housing" europe "animal welfare" retrieves records whose indexing contains all three search terms together.

Note. You can type AND in either upper or lower case as shown here:

"cattle housing" and europe AND "animal welfare"


Use this Boolean operator to modify or refine your search.


You want to find research papers about cattle or sheep or horses. If you type the three terms: cattle sheep horses, CAB Direct retrieves only records that contain all three terms. In other words, they would be ANDed together.

This search would not find records that contain just one or two of the terms. This would seriously limit the search. In this example, you want to find records that contain all the words or any of the words. To do this, you can use the OR operator, i.e.

cattle OR sheep OR horses

This search finds records that contain one or more of the three search terms. The OR operator “expands” the search. The search gets larger as you OR more terms together.


Use this Boolean operator to exclude terms from your search.


You are interested in research papers about breeding but not genetics. To do this, use the NOT operator:

breeding NOT genetics

This search finds all records containing the word breeding, but excludes any record that includes the word genetics. The NOT operator restricts your search, making it smaller.

Tip. Use the NOT operator carefully, as it is possible to lose relevant records by accident.