Telecommunication systems :  Units 5 - 6; Noise and interference and digital systems /  [Book]. 
The Open University.  
 - Milton Keynes :   The Open University Press,   1976. 
 - 55p. :  ill. (some col.) ;  30 cm. 
<br/><br/><label>ISBN: </label>0335061028 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telecommunication systems.