TY  - GEN
AU  - DHALIWAL, G S
AU  - KUKAL, S S
TI  - ESSENTIAL OF ENVIRONMENTAL SCIENCE
U1  - 577 DHA/ES 
CY  - LUDHIANA, KALYANI
KW  - ECOSYSTEM
KW  - ENVIRONMENTAL POLLUTION
KW  - NATURAL RESOURCES
KW  - SCOP ANDSIGNIFICANCE
ER  -