TY  - BOOK
AU  - Asthana, D. K.
AU  - ASTHANA, MEERA
TI  - Textbook of Environmental studies 
SN  - 8121924641
U1  - 628 
PY  - 2006///
CY  - New Delhi
PB  - S. Chand & Company LTD.
KW  -  Environmental engineering
KW  -  Environmental protection
KW  - Environmental sciences
ER  -