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

MLA (8th ed.) Citation

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