Board, N. R. C. T. R. (1992). Traffic control devices and highway visibility. Washington, DC : National Academy Press.
Chicago-referens (17:e uppl.)Board, National Research Council. Transportation Research. Traffic Control Devices and Highway Visibility. Washington, DC : National Academy Press, 1992.
MLA-referens (9:e uppl.)Board, National Research Council. Transportation Research. Traffic Control Devices and Highway Visibility. Washington, DC : National Academy Press, 1992.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.