Bellamy, John. <br/><br/>
Digital telephony / 
John Bellamy. 
 - 2nd ed. 
 - New York :  John Wiley & Sons,  1991. 
 - xix, 572 p. :  ill. ;  25 cm. 
<br/><br/><label>ISBN: </label>0471620564 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Digital telephone systems.