Boolean Search Operators
You can use the following Boolean search operators to define the relationships between your keywords and narrow or broaden your search results.
Operator | Example | Finds articles with... |
---|---|---|
AND | badgers AND tuberculosis | both the word badgers and the word tuberculosis |
OR | badgers AND (tuberculosis OR TB) | either the word tuberculosis or the word TB and the word badgers |
- | badgers AND Tuberculosis -vaccination | the words badgers, tuberculosis but not the word vaccination |
Note: the hyphen (or minus) symbol is used as the NOT operator.
When you use multiple operators in your search, ScienceDirect applies them in this order:
When your search query includes multiple Boolean operators, use brackets " ( )" to help the search engine group them in a way that is relevant for your research:
"badgers" OR "meles meles" AND tuberculosis finds all documents in which the phrase "meles meles" AND the word tuberculosis are both present as well as all documents in which the word badgers is present.
(badgers OR "meles meles") AND tuberculosis will only find documents that include the word tuberculosis in addition to either the word badgers or the phrase "meles meles".
Searching for phrases/exact phrases
Use quotation marks around words to find documents where your search words appear together
To find results that contain your exact phrase, including punctuation, put curly brackets around your keywords.
Using wildcards
If you are not sure of a spelling you can use an asterisk (*) or question mark (?)
Use an asterisk (*) as a multi-character wildcard to replace characters anywhere in a word.
Use a question mark to replace exactly one character in a word. Use one question mark for each character you want to replace.
Special characters
Plurals of words
ScienceDirect automatically looks for the plural of most keywords
British vs American Spellings
ScienceDirect looks for both British and American spellings