TY  - BOOK
AU  - Ryan,Beverley A.
AU  - Mara,David Duncan
ED  - World Bank.
ED  - United Nations Development Programme.
ED  - International Drinking Water Supply and Sanitation Decade.
TI  - Pit latrine ventilation: field investigation methodology 
PY  - 1983///
CY  - Washington, D.C.
PB  - World Bank
KW  - Toilet facilities
ER  -