Verderber, Rudolph F. <br/><br/>
The Challenge of Effective Speaking in a Digital Age/ 
Rudolph F. Verderber 
 - USA:  Cengage Learning,  c2015. 
 - xx, 369 pages:  Colored Illustration;  27.5cm 
<br/><br/> Includes Glossary and Index 
<br/><br/><label>ISBN: </label>9781285094847 
<br/><br/><label>Dewey Class. No.: </label>DC 808.51  / V58