Finding reputable sources can be difficult. For academic and scientific research papers it's best to stick to peer-reviewed databases like Library Quick Search, UTSA Libraries databases, and Google Scholar.
Racheli Rottner/Wikimedia Israel, via Wikimedia Commons
Use these operators to perform more powerful searches
AND – combine terms, e.g. memory AND sleep
OR – include synonym terms, e .g. (coke OR soda OR pop OR "soft drinks") AND sleep
NOT – exclude terms, e.g. sleep NOT apnea
* (or ?) – wildcard, e.g. medic*
“[quotes]” – phrase search, e.g. “civil rights”