APA (7 वां संस्करण) प्रशस्ति पत्र

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

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

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

एमएलए (9वां संस्करण) प्रशस्ति पत्र

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