Chang, V. N., Decker, C. L., & Scott, S. T. (2009). Developing helping skills: A step-by-step approach. Brooks/Cole Cengage Learning.
Chicago-viite (17. p.)Chang, Valerie Nash, Carol L. Decker, ja Sheryn Thompson Scott. Developing Helping Skills: A Step-by-step Approach. Belmont, CA: Brooks/Cole Cengage Learning, 2009.
MLA-viite (9. p.)Chang, Valerie Nash, et al. Developing Helping Skills: A Step-by-step Approach. Brooks/Cole Cengage Learning, 2009.
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