APA (see APA, section 6.17, p. 178; APA Style FAQ) suggests that secondary sources should be used sparingly, especially when the full-text of the original source is available. However, there are instances in which the original source is:
In these cases, you would list the secondary source in the reference list, name the original work and use an in-text citation for the secondary source.
Here are some examples:
Citing an original work from a secondary source:
a. Secondary citation within the text:
According to Freud (as cited in Skinner, 1923), the characteristics ….
b. The document used is cited in the reference list:
Skinner, B. F. (1974). About behavioralism. New York, NY: Knopf.
Notice that Freud is mentioned in the body of the paper so the reader would understand that any ideas being cited even though the actual book that discussed Freud's ideas was actual written by Skinner.
Citing an unpublished manuscript from an archival collection
Original documents for unpublished and archived sources are difficult to retrieve so secondary sources may be used. An example includes a diary entry like the example in APA (6th ed.), p. 178, section 6.17.
a. Secondary citation ithin the text (direct APA example, p. 178)
Allport's diary (as cited in Nicholson, 2003).
b. The actual document used is cited in the reference list
Nicholson, I. (2003). Inventing personality: Gordon Allport and the science of selfhood. Washington, DC, US: American Psychological
Association. doi: 10.1037/10514-000