Patents for invention :  abridgements of specifications 2500/30000 / 
Patent Office of India 
 - Calcutta :  Govt. Press,  [n. d] 
 - 82 p. ;  24 cm. 
<br/><br/> Aircraft and ship, Aeronautics, Ships and Boats 
<br/><br/><label>Dewey Class. No.: </label>608.754