Das, P.N. <br/><br/>
An introduction to automatic telephony [for the Undergraduate students of telecommunication and electrical engineering]/ 
P.N. Das 
 - 4th ed. 
 - Calcutta:  Modern Book,  1975 
 - vii, 237 p.;  21 cm. 
<br/><br/> Includes index 
<br/><br/>Includes bibliography: p. 232-235 
<br/><br/><label>ISBN: </label> Rs. 12.50 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephone, Dial<br/>Telephone relays<br/>Telephone switching systems, electronic<br/>Telephone lines<br/>Telephone, Automatic<br/>Telephone stations
<br/><br/><label>Dewey Class. No.: </label>621.3877