Verderber, Rudolph F. The Challenge of effective speaking in a digital age Rudolph F. Verderber, Deanna D. Sellnow, Kathleen S. Verderber [edited by] Kassi Radomski, Cara Douglass-Graff. - 16th Ed - Boston MA Cengage Learning c2015. - xx 369p ill col 28cm Included index ISBN: 9781285094847 Subjects--Topical Terms: Public speaking.