APA (7th ed.) Citation

Combs, A. W., Avila, D. L., & Purkey, W. W. (1971). Helping relationships: Basic concepts for the helping professions. Allyn and Bacon.

Chicago Style (17th ed.) Citation

Combs, Arthur W., Donald L. Avila, and William W. Purkey. Helping Relationships: Basic Concepts for the Helping Professions. Boston: Allyn and Bacon, 1971.

MLA (9th ed.) Citation

Combs, Arthur W., et al. Helping Relationships: Basic Concepts for the Helping Professions. Allyn and Bacon, 1971.