Organisation for Economic Co-operation and Development. (1972). Speed limits outside built-up areas.
Dyfyniad Arddull ChicagoOrganisation for Economic Co-operation and Development. Speed Limits Outside Built-up Areas. [Paris, 1972.
Dyfyniad MLAOrganisation for Economic Co-operation and Development. Speed Limits Outside Built-up Areas. 1972.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.