APA (7th ed.) Zitazioa

Hoppock, R. (1949). Group Guidance: Principles, techniques and evaluation. McGraw-Hill.

Chicago Style (17th ed.) Zitazioa

Hoppock, Robert. Group Guidance: Principles, Techniques and Evaluation. Nueva York: McGraw-Hill, 1949.

MLA (9th ed.) Zitazioa

Hoppock, Robert. Group Guidance: Principles, Techniques and Evaluation. McGraw-Hill, 1949.