Hardwick, Steve  <br/><br/>
ISDN design:   A practical approach  

 - New York:   Academic Press, Inc.,   1989 
 - x, 152p.  
<br/><br/><label>ISBN: </label>0-12-324970-8 
<br/><br/><label>Universal Decimal Class. No.: </label>D 681.324:621.39  / M9