Citing a source within a source (secondary sources)
For sources that you have not actually seen but which are referred to in another work, list the secondary source (the source you have read) in the Reference List. In-text, name the original work and give a citation for the secondary source.
For example, if Bennett's work is cited in a book by Stone (2013) and you didn't read Bennett's original work, list the source you did read (in this case Stone) in the Reference List.
Bennett (as cited in Stone, 2013) defined ...
Stone, R. J. (2013). Managing human resources (4th ed.). Milton, Australia: Wiley.
See the entry on Secondary Sources in the APA style blog for more information