(2007). Principles of town water supply and sanitation. Washington DC: The World Bank.
Dyfyniad Arddull ChicagoPrinciples of Town Water Supply and Sanitation. Washington DC: The World Bank, 2007.
Dyfyniad MLAPrinciples of Town Water Supply and Sanitation. Washington DC: The World Bank, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.