If you are searching for a particular term or word stem and you don’t know how it begins or ends or you don’t want to narrow this down, use the asterisk * as a placeholder.
If you enter "NOT " directly before a word, you exclude sites that include that word from the search.
Search for phrases
If you put a group of words in quotation marks " ", the search will be performed on exactly these words in exactly the order given.
Example: A query for "infection" NOT "immunity" will search for "infection," but will exclude references to "immunity".