Kessler, Gary C. , <br/><br/>
ISDN :  concepts, facilities, and services / 
Gary C Kessler. 
 - McGraw-Hill communications series .
<br/><br/><label>ISBN: </label>0070342423 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Integrated services digital networks.
<br/><br/><label>LC Class. No.: </label>TK5103.7   / .K47 1990