Ryan, B. A. (1983). Ventilated improved pit latrines: Vent pipe design guidelines. IBRD/World Bank.
Citación estilo ChicagoRyan, Beverley A. Ventilated Improved Pit Latrines: Vent Pipe Design Guidelines. Washington, D.C: IBRD/World Bank, 1983.
Cita MLARyan, Beverley A. Ventilated Improved Pit Latrines: Vent Pipe Design Guidelines. IBRD/World Bank, 1983.
Warning: These citations may not always be 100% accurate.