Stallings, William.  <br/><br/>
ISDN and Broadband ISDN /  
Stallings William. 
 - 2 edition. 
 - New York :   Macmillan,   1992. 
 - XIX, 633 s.:   il.;   22 cm. 
<br/><br/><label>ISBN: </label>0029463998