Gaya APA

Prochaska, J, O. (1979). Systems of Psychotherapy : a. transtheoretical analysis (The Dorsey Series in Psychology). illinois: The Dorsey Press.

Gaya MLA

Prochaska, James, O.. "Systems of Psychotherapy : a. transtheoretical analysis". The Dorsey Series in Psychology illinois: The Dorsey Press, 1979. Text.