Sharma, P D <br/><br/>
Ecology and environment 

 - 6th 
 - Meerut  Rakesh Kumar Rastogi  1993 
 - xv,519 
<br/><br/><label>ISBN: </label>81-7133-183-1 
<br/><br/><label>Dewey Class. No.: </label>581.521 Sh