Chhatwal, G.R. <br/><br/>
Encyclopaedia of world great scientists, Vol.8 

 - New Delhi  Anmol  1992 
 - [4], pp. 725-1114 
<br/><br/><label>ISBN: </label>8170416507 
<br/><br/><label>Dewey Class. No.: </label>509.03  / ENC