Cita APA (7th ed.)

Berg, R. C., & Landreth, G. L. (1990). Group counseling: Concepts and procedures (2nd ed.). Accelerated Development.

Cita Chicago (17th ed.)

Berg, Robert C., i Garry L. Landreth. Group Counseling: Concepts and Procedures. 2nd ed. Muncie, Ind: Accelerated Development, 1990.

Cita MLA (9th ed.)

Berg, Robert C., i Garry L. Landreth. Group Counseling: Concepts and Procedures. 2nd ed. Accelerated Development, 1990.