Bala Krishnan Nair N. <br/><br/>
Paristhitivijnanam / 
by Bala Krishnan Nair N. 
 - Thiruvananthapuram :  Kerala Bhasha Institute,  1971. 
<br/><br/><br/>In Malayalam 
<br/><br/><label>Subjects--Index Terms: </label>Biology Ecology