World Health Organization. (2011). Guide to ship sanitation. World Health Organization.
Dyfyniad Arddull ChicagoWorld Health Organization. Guide to Ship Sanitation. Geneva, Switzerland: World Health Organization, 2011.
Dyfyniad MLAWorld Health Organization. Guide to Ship Sanitation. World Health Organization, 2011.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.