Enviroment problems and solutions 
Asthana D.K & Asthana Meera 
 - 3rd 
 - New Delhi  S.Chand & Company Pvt Ltd  2008 
 - xix, 434p.  ills 
<br/><br/><label>ISBN: </label>8121916542 
<br/><br/><label>LC Class. No.: </label>TD170.7 .A88 2008