Verma, P S & Agarwal, V K <br/><br/>
Environmental biology 

 -  S Chand & Co. Ltd., New Delhi  2006 
 - 591 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology; Biology
<br/><br/><label>Dewey Class. No.: </label>574.5  VER-E