Trecker, H. B. (1972). Social group work, principles and practices (Thoroughly rewritten, updated and expanded.). Association Press.
Chicago-Zitierstil (17. Ausg.)Trecker, Harleigh Bradley. Social Group Work, Principles and Practices. Thoroughly rewritten, updated and expanded. New York: Association Press, 1972.
MLA-Zitierstil (8. Ausg.)Trecker, Harleigh Bradley. Social Group Work, Principles and Practices. Thoroughly rewritten, updated and expanded. Association Press, 1972.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.