Verma,P.S, <br/><br/>
Principles of Ecology  

 - 4th /   1992. 
 - N.Delhi:  S.Chand & company ltd,  1992. 
 - 591 p. 
<br/><br/><label>Subjects--Personal Names: </label><br/>Zoology, Ecology. 
<br/><br/><label>Dewey Class. No.: </label>574.5