Singh,H.S.  x <br/><br/>
Principles of environmental conservation  x 

 - x 
 - Dehra Dun  International Book Distributors  1989 
 - vi,273 
<br/><br/>x 
<br/><br/><label>ISBN: </label>8770891019 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Environment Pollution 
<br/><br/><label>Dewey Class. No.: </label>628.5/S617p