Bellamy J. C. <br/><br/>
Digital Telephony  Textual Documents  
Bellamy J. C. 
 - 3rd ED 
 -  Wiley India Pub.  2013 
 - 643 
<br/><br/><label>ISBN: </label>978-81-245-0929-4   
<br/><br/><label>Dewey Class. No.: </label>004.64