Patents for inventions abridgment of specification 3000 - 35000 / 
patent office, Govt. of India. 
 - Delhi :  Govt. Press,  1957. 
 - 27 p. ;  24 cm. 
<br/><br/> Group II. - Sanitation (1) Closets, baths and like sanitari applicances.(2) Drains and Sewers.(3)Sewage, treatment of.(4)Water and unspecificafied liquids, purifying and sottenry. 
<br/><br/><label>Dewey Class. No.: </label>608.754