Combs, A. W., Avila, D. L., & Purkey, W. W. (1971). Helping relationships: Basic concepts for the helping professions. Allyn and Bacon.
Chicago-viite (17. p.)Combs, Arthur W., Donald L. Avila, ja William W. Purkey. Helping Relationships: Basic Concepts for the Helping Professions. Boston: Allyn and Bacon, 1971.
MLA-viite (9. p.)Combs, Arthur W., et al. Helping Relationships: Basic Concepts for the Helping Professions. Allyn and Bacon, 1971.
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