TY  - BOOK
AU  - Duggal,K.N, x
AU  - x
TI  - Elements of environmental engineering: x
SN  - 8121915473
U1  - 628/D868e 
PY  - 1998///
CY  - New Delhi
PB  - S.Chand
KW  - Environmental engineering
KW  - Engineering
N1  - x
ER  -