Open University T321 <br/><br/>
Telecommunication systems course : units 7-9. Telephone systems : study supplement  [Books]. 
Open University. 
 - Milton Keynes  Open University Press  1976 
 - Pages: 43 
<br/><br/><label>ISBN: </label>0335061036  0.00 
<br/><br/><label>Subjects--Personal Names: </label><br/>Telecommunication systems.
<br/><br/><label>Dewey Class. No.: </label>TK/5101  / TEL