Biswas, Nripendra Nath,  1928- <br/><br/>
Principles of telephony / 
N. N. Biswas. 
 - New York :  Asia Pub. House,  c1970. 
 - vii, 138 p. :  ill. ;  24 cm. 
<br/><br/><label>ISBN: </label>021022312X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Telephone, Automatic.
<br/><br/><label>Dewey Class. No.: </label>621.385  / BIP 1970