National Joint Committee on Uniform Traffic Control Devices & American Association of State Highway Officials. (1971). Manual on uniform traffic control devices for streets and highways. Federal Highway Administration; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.
Cita Chicago (17th ed.)National Joint Committee on Uniform Traffic Control Devices i American Association of State Highway Officials. Manual on Uniform Traffic Control Devices for Streets and Highways. Washington]: Federal Highway Administration; [for sale by the Supt. of Docs., U.S. Govt. Print. Off, 1971.
Cita MLA (9th ed.)National Joint Committee on Uniform Traffic Control Devices i American Association of State Highway Officials. Manual on Uniform Traffic Control Devices for Streets and Highways. Federal Highway Administration; [for sale by the Supt. of Docs., U.S. Govt. Print. Off, 1971.