Duggal, K. N.  <br/><br/>
Elemets of environmental engineering / 

 - New Delhi,   S.Chand and Company Ltd.   c1966. 
 - 496p. ;  ill. ;  22 cm.  
<br/><br/><label>ISBN: </label>8121915473 
<br/><br/><label>LC Class. No.: </label>3301 
<br/><br/><label>Dewey Class. No.: </label>620.819