To find a single study article in the psychology available at the APUS library, use PsycARTICLES (which you can access from the menu bar at the top of the Library Homepage under Research > Research Tools > Databases).
From the advanced search screen, locate the “Methodology” search box, check the "select all" button and then deselect: literature review, meta analysis, metasynthesis, and systematic review.
More information about APUS library psychology resources is available in the Psychology Research Guide. From the menu bar at the top of the Library Homepage, select Research > Research Tools > Research Guides.