Griffiths, John M..  <br/><br/>
ISDN Explained :   Worldwide Network and Applications Technology /   1 t. 
Griffiths John M.. 
 - 3rd edition. 
 - Chichester :   Wiley & Sons,   1998. 
 - XIV, 291 s.:   il.;   25 cm. 
<br/><br/><label>ISBN: </label>0471979058