APA aipamena

Verderber, R. F. (1988). The challenge of effective speaking (Seventh edition.). Wadsworth Publishing Company.

Chicago Style aipamena

Verderber, Rudolph F. The Challenge of Effective Speaking. Seventh edition. Belmont, California: Wadsworth Publishing Company, 1988.

MLA aipamena

Verderber, Rudolph F. The Challenge of Effective Speaking. Seventh edition. Wadsworth Publishing Company, 1988.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.