Use USC Libraries Search on the Libraries' homepage and type in your search terms then click the magnifying glass to get results.

On the results page you will see sidebar on the left side of the screen labeled REFINE MY SEARCH. 

Select "Peer-reviewed journals" and you will have a subset of the results list that are from scholarly or peer reviewed journals. (Peer viewed journals are sometimes referred to as "refereed")

Many subject specific databases also include an option to limit to peer reviewed (or academic or scholarly) articles.