Combine concepts using AND to narrow your search
e.g. mathematics modeling AND biology
Combine synonyms using OR to expand your search
e.g. positron emission tomography OR PET
To do phrase searching, words in that order, use quotes
e.g. "group theory"
Use parenthesis to group phrases with similar meaning combined with OR/AND.
medicine AND (positron emission tomography OR PET)
The asterisk * symbol will search for all variations of a word.
e.g. optic* will search for optic, optics, and optical