Corey, G., Corey, M. S., Callanan, P., & Russell, J. M. (2015). Group techniques (Fourth edition.). Brooks/Cole, Cengage Learning.
Dyfyniad Arddull ChicagoCorey, Gerald, Marianne Schneider Corey, Patrick Callanan, and J. Michael Russell. Group Techniques. Fourth edition. Stamford, CT: Brooks/Cole, Cengage Learning, 2015.
Dyfyniad MLACorey, Gerald, et al. Group Techniques. Fourth edition. Brooks/Cole, Cengage Learning, 2015.
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