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Peer reviewed articles are also known as "refereed" articles. They undergo a stricter editorial process.
The Cal Poly Pomona Library website defines "peer reviewed" or "refereed" articles as articles that "have been read and evaluated (refereed) by scholars/experts in that field to make sure that published articles reflect solid scholarship and advance the state of knowledge in a discipline."
The University Library Catalog (OneSearch) and databases allow you to adjust your search filters to find only peer reviewed articles.