Gaya APA

Sundel, M., Sundel, S, S. (2005). Behavior change in the human services : behavioral and cognitive principles and applications (5). United States of America: Sage Publications.

Gaya MLA

Sundel, Martin., Sundel, Sandra, S.. "Behavior change in the human services : behavioral and cognitive principles and applications". 5 United States of America: Sage Publications, 2005. Text.