Groups sources drawn from a site built specifically to explain psychology to students and general readers, such as Simply Psychology or LibreTexts, plus a primary historical text hosted by an educational archive for the same teaching purpose. These sources are written by and for the discipline rather than as general-purpose encyclopedia coverage, and they are the atlas's preferred citation for a theory, a school of thought or a psychologist's own body of work when a dedicated explainer exists. A source that is itself the peer-reviewed record of a single study belongs under journal article instead.