Verma, P. S. <br/><br/>
Rinciples of ecology  : environmental biology 
P. S. Verma and V. K. Agarwal 
 - 3rd ed. 
 - New Delhi  S. Chand  1986 
 - 588p. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label>
<br/><br/><label>Subjects--Topical Terms: </label><br/>Biology
<br/><br/><label>Dewey Class. No.: </label>577  / V522