Held, Gil. <br/><br/>
Voice & Data Internetworking  
Gil Held,  
 - 3rd ed.  
 - New Delhi :  Tata McGraw-Hill Publishing Company Limited,   c2001.  
 - xviii,397 p.:  [36] 
<br/><br/><label>ISBN: </label>0070447446 
<br/><br/><label>Dewey Class. No.: </label>004.69  / HEL/VOI