Biswas, N.N. <br/><br/>
Principles of telephony 
/ by N.N. Biswas 
 - New York:   Asia Publication House,   1970. 
 - 136p. 
<br/><br/><label>ISBN: </label>818527309-X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Applied physics<br/>Group sector<br/>Manual telephony<br/>Telephone instruments
<br/><br/><label>Dewey Class. No.: </label>621.385  / BIS/P