Biswas, N N  <br/><br/>
Principles of telephony  

 - Bombay:  Asia Publishing House,   1970 
 - 136p. 
<br/><br/><label>ISBN: </label>0-210-22312-X  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephony 
<br/><br/><label>Universal Decimal Class. No.: </label>621.395  / L0