Das, P.N. <br/><br/>
An introduction to manual telephony:  for the undergraduate students of telecommunication and electrical engineering/ 
P.N. Das 
 - Calcutta:  Modern Book,  1967 
 - 138 p.;  22 cm. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label> Rs. 10.00 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephone<br/>Telephone system<br/>Telephone--Signalling<br/>Telephone lines
<br/><br/><label>Dewey Class. No.: </label>621.3854