00302nam a2200109Ia 4500008004100000082002500041100003200066245004100098250000900139260003600148300000800184240913s9999||||xx |||||||||||||| ||und||  aGS    372.357  AST/A  aK Asthana and Meera Asthana 2aA Text book of environmental studies  aNULL  bS Chand and CoaNew Delhic2006  a460