Gaya APA

Posthuma, B, W. (1996). Small Groups In Counseling and Therapy: Process and Leadership (Ed. 2). United States Of America: Allyn & Bacon.

Gaya MLA

Posthuma, Barbara, W.. "Small Groups In Counseling and Therapy: Process and Leadership". Ed. 2 United States Of America: Allyn & Bacon, 1996. Buku PSI.