APA (7th ed.) Zitazioa

Verderber, R. F. (1976). The challenge of effective speaking (3rd ed.). Wadsworth.

Chicago Style (17th ed.) Zitazioa

Verderber, Rudolph F. The Challenge of Effective Speaking. 3rd ed. Califonia: Wadsworth, 1976.

MLA (9th ed.) Zitazioa

Verderber, Rudolph F. The Challenge of Effective Speaking. 3rd ed. Wadsworth, 1976.