Gaya APA

Kanfer, F, H., Goldstein, A, P. (1991). Helping People Change : A Textbook of Methods 4'th Ed. (4). New York: Pergamon Press.

Gaya MLA

Kanfer, Frederick, H.., Goldstein, Arnold, P.. "Helping People Change : A Textbook of Methods 4'th Ed.". 4 New York: Pergamon Press, 1991. Text.