J.M.Griffiths <br/><br/>
Local Telecommunications2:Into The  Digital Era 

 - 
 -  Peter Peregrinus  1986 
 - 293 
<br/><br/>  
<br/><br/><label>ISBN: </label>0-86341-080-4 
<br/><br/><label>Dewey Class. No.: </label>621.39