AND
term1 AND term2
Both terms must be included
OR
term1 OR term2
Either term
NOT
term1 NOT term2
term2 must not appear
""
"term1 term2"
Exact match
()
term1 AND (term2 OR term3)
Grouping terms
?
withdr?w
Single letter wildcard (withdraw, withdrew)
"..."~n
"term1 term2"~n
Proximity (term1 within n words of term2)