TY  - BOOK
AU  - Asthana, D.K
AU  - Asthana, Meera
TI  - Textbook of environmental studies
SN  - 978-81-219-2764-2
U1  - 344.54046 
PY  - 2022///
CY  - New Delhi
PB  - S Chand and Company Limited
ER  -