Das, P. N <br/><br/>
Line telegraphy 
P. N  Das, 
 - Calcutta:   [s.n.],  1965.       
 - 197 p     Includes index        
<br/><br/><label>Subjects--Topical Terms: </label><br/>Line telegraphy
<br/><br/><label>Dewey Class. No.: </label>TBB D66,47   / K5