TY  - BOOK
AU  - Bureau of Indian Standards[BIS]
TI  - IS:11401-(Pt.2)-1990. Indian standard general requirements for slow sand filters. Pt.2 : design, construction, operation and maintenance
U1  - IS CODE 
PY  - 1990///
CY  - New Delhi
PB  - Bureau of Indian Standards
N1  - ENG
ER  -