Verma, P. S. <br/><br/>
Environmental biology (Principles of ecology) / 
P. S. Verma, V. K. Agarwal. 
 - Rev.  ed. 
 - New Delhi :  S. Chand,  1993. 
 - viii, 591  p. 
<br/><br/><label>ISBN: </label>8121908590 :  KES 405 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology.