APA (7th ed.) Zitazioa

Verderber, R. F. (1982). The challenge of effective speaking (5th ed.). Wadsworth.

Chicago Style (17th ed.) Zitazioa

Verderber, Rudolph F. The Challenge of Effective Speaking. 5th ed. Califonia: Wadsworth, 1982.

MLA (9th ed.) Zitazioa

Verderber, Rudolph F. The Challenge of Effective Speaking. 5th ed. Wadsworth, 1982.