Roddy, Dennis, <br/><br/>
Electronic communications / 
[by] Dennis Roddy, John Coolen. 
 - 4th ed. 
 - New Delhi  Pearson  c1995. 
 - ix, 723 p. :  ill. ; 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>9788177585582 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telecommunication.
<br/><br/><label>Dewey Class. No.: </label>621.382 ROD/E