Gopal, Brij <br/><br/>
Elements of ecology / 
Brij Gopal, N. Bhardwaj 
 - Ghaziabad, India :  Vikas Publishing House PVT LTD.,  1979 
 - 200 p. :  ill. ;  21 cm. 
<br/><br/><label>ISBN: </label>0706915607 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology