Langley, Graham. <br/><br/>
Telecommunications primer /  [Book]. 
Graham Langley. 
 - 2nd ed. 
 - London :   Pitman,   1986. 
 - vi,170p. :   ill., maps ;   25cm. 
<br/><br/> Previous ed.: 1983.  Includes index. 
<br/><br/><label>ISBN: </label>0273024787 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telecommunication systems.
<br/><br/><label>Subjects--Index Terms: </label>Telecommunication systems