Sundel, M., & Sundel, S. S. (1999). Behavior change in the human services: An introduction to principles and applications. SAGE Pub.
Citazione stile Chigago Style (17a edizione)Sundel, Martin, e Sandra S. Sundel. Behavior Change in the Human Services: An Introduction to Principles and Applications. Thousand Oaks, Calif: SAGE Pub, 1999.
Citatione MLA (9a ed.)Sundel, Martin, e Sandra S. Sundel. Behavior Change in the Human Services: An Introduction to Principles and Applications. SAGE Pub, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.