• word1 word2 word3 -- searches for documents containing ALL of the listed keywords
• "word1 word2" -- searches for documents containing the specified phrase, that is containing both word1 and word2 where word2 immediately follows word1
• (word1 and not word2) or (word3 and word4) -- searches for documents for which the specified boolean expresion is true; please note that you can use the and, or, not operators as well as parentheses

You can also use wildcard characters (? and *), e.g. entering comput* will match all of the following words: computer, computers, computing. Another example is *tribut? which will match words like: contribute, attribute.

Please note that you can mix the above syntax, e.g.: "word1 word2" or "word1 word3". Another example: "*ord?" and not word1