Ephross, P. H., & Vassil, T. V. (2005). Groups that work: Structure and process (2nd ed.). New York: Columbia University Press.
Παραπομπή Chicago StyleEphross, Paul H., και Thomas V. Vassil. Groups That Work: Structure and Process. 2nd ed. New York: Columbia University Press, 2005.
Παραπομπή MLAEphross, Paul H., και Thomas V. Vassil. Groups That Work: Structure and Process. 2nd ed. New York: Columbia University Press, 2005.
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