Roddy, Dennis. <br/><br/>
Electronic communications / 
Dennis Roddy and John Coolen. 
 - New Delhi :  Prentice Hall,  1995. 
 - 4th ed. ix, 820 p. :  ill. ;  26 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>8120309847 (pbk.)