TY  - BOOK
AU  - Duggal, K.N.
TI  - Elements of environmental engineering 
SN  - 81-219-1547-3
PY  - 1996///
CY  - New Delhi
PB  - S.Chand & Co.
KW  - Environmental Engineering
KW  - Water Supply
KW  - Sewage Disposal
KW  - Environmental sanitation
ER  -