Verma, P S; Agarwal, V K <br/><br/>
Concepts of ecology: Environmental biology 

 -  S Chand & Co. Ltd., New Delhi  1998 
 - 264 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology; Biology
<br/><br/><label>Dewey Class. No.: </label>PG 574.5  VER-C