APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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