Heldman, Robert K..  <br/><br/>
Telecommunications Management Planning :   ISDN Networks. Products and Services /  
Heldman Robert K.. 
 - Blue Ridge Summit, PA :   TAB Books,   1987. 
 - XVIII, 734 s.:   il.;   24 cm. 
<br/><br/><label>ISBN: </label>0830628649