Shrader, Robert L. <br/><br/>
Electronic communications. 

 - 6th edition 
 - xiii,713 p. (pb)  23cm. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label>0-07-057157-0 
<br/><br/><label>Dewey Class. No.: </label>621.381 Sh83 1991