Cunard, R. A. (1990). Maintenance management of street and highway signs. Transportation Research Board, National Research Council.
Dyfyniad Arddull ChicagoCunard, Richard A. Maintenance Management of Street and Highway Signs. Washington, D.C: Transportation Research Board, National Research Council, 1990.
Dyfyniad MLACunard, Richard A. Maintenance Management of Street and Highway Signs. Transportation Research Board, National Research Council, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.