Gopal, Brij; Bhardwaj, N <br/><br/>
Elements of ecology 

 -  Vikas Publishing House Pvt. Ltd., New Delhi  1979 
 - 200 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology; Biology
<br/><br/><label>Dewey Class. No.: </label>PG 574.5  GOP-E