Cunard, R. A. (1990). Maintenance management of street and highway signs. Transportation Research Board, National Research Council.
Chicago-referens (17:e uppl.)Cunard, Richard A. Maintenance Management of Street and Highway Signs. Washington, D.C: Transportation Research Board, National Research Council, 1990.
MLA-referens (9:e uppl.)Cunard, Richard A. Maintenance Management of Street and Highway Signs. Transportation Research Board, National Research Council, 1990.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.