Sundel, M., & Sundel, S. S. (2005). Behavior change in the human services: Behavioral and cognitive principles and applications (5th ed.). Sage Publications.

Sundel, Martin, and Sandra Stone Sundel. Behavior Change in the Human Services: Behavioral and Cognitive Principles and Applications. 5th ed. Thousand Oaks, Calif: Sage Publications, 2005.

Sundel, Martin, and Sandra Stone Sundel. Behavior Change in the Human Services: Behavioral and Cognitive Principles and Applications. 5th ed. Sage Publications, 2005.