Boolean search queries can help you refine your search results, either by adding or removing unwanted results from the list.
Exact matches
Put search terms in between quotes to find an exact match, i.e. "moon":
Combining terms
Use the ampersand (&) or AND to combine search terms, i.e. "space AND national":
Alternative terms
Use the line (|) or OR to match either item, i.e. "space OR national":
Grouping terms
Use parentheses to group search terms, i.e. "moon (space | national)":
Excluding terms
Use the exclamation mark (!) or NOT to exclude a search term, i.e. "moon NOT space":
Partial matches
Put search terms in between asterisks to find a partial match, i.e. "moon *space*":
Abbreviations
Type abbreviation in upper case to get them recognized, i.e. "NASA":
Synonyms
Hover over a word with (+ X) next to it to view and edit synonyms & suggestions, i.e. "moon (+2)", and to manually add your own
You can always see your last search results and tips on how to search by clicking on the empty search box: