"In scholarly work, a primary source reports original content; a secondary source refers to content first reported in another source" (258).
Publication Manual of the American Psychological Association. 7th ed., American Psychological Association, 2020
"[A] journal article about original research . . . written by the researcher" (38).
Landrum, R. Eric. Undergraduate Writing in Psychology: Learning to Tell the Scientific Story. Rev. ed. American Psychological Association, 2012