Use filters to narrow your results to peer-reviewed resources:
In the library catalog, the "Peer-reviewed Journals" filter is located on the right-hand side of the search results list, under the "Availability" section (see image above). Individual records that are peer-reviewed are labelled in the results list by a purple eyeball and book icon (below image)
In a database the filter (in the image below from EBSCO the filter is called "Scholarly (Peer Reviewed) Journals" but may be titled differently in each database) will be located in a menu on the side of the search results list.
Many of our databases have this button, which searches for the full-text of the article in our collections. If we don't have it electronically, look for the "Request article scan" link in the "Get It" section.