Cita APA (7a ed.)

Carkhuff, R. R., & Carkhuff, R. R. C. (2010). The art of helping (9th ed.). HRD Press.

Cita Chicago Style (17a ed.)

Carkhuff, Robert R., y Robert R Contributor Carkhuff. The Art of Helping. 9th ed. Amherst: HRD Press, 2010.

Cita MLA (9a ed.)

Carkhuff, Robert R., y Robert R Contributor Carkhuff. The Art of Helping. 9th ed. HRD Press, 2010.