Corey, G. (1990). Theory and practice of group counselling (3rd ed.). Brooks/Cole Publishing.
Chicago Style (17th ed.) ZitazioaCorey, Gerald. Theory and Practice of Group Counselling. 3rd ed. California.: Brooks/Cole Publishing, 1990.
MLA (9th ed.) ZitazioaCorey, Gerald. Theory and Practice of Group Counselling. 3rd ed. Brooks/Cole Publishing, 1990.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.