Das, P. N. <br/><br/>
An introduction to automatic telephony;  for the undergraduate students of tele-communication and electrical engineering. 

 - [1st ed.] 
 - Calcutta,  Modern Book Agency  [1963] 
 - 212 p.  illus.  22 cm. 
<br/><br/>Bibliography: p. 207-208. 
<br/><br/><label>LCCN: </label>sa 64000289  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephone, Automatic.
<br/><br/><label>LC Class. No.: </label>TK6397  / .D3