United States. Federal Highway Administration. (1989). Manual on uniform traffic control devices: For streets and highways (1988 ed.). U.S. Dept. of Transportation, Federal Highway Administration For sale by the Supt. of Docs., U.S. G.P.O.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Federal Highway Administration. Manual on Uniform Traffic Control Devices: For Streets and Highways. 1988 ed. Washington, D.C: U.S. Dept. of Transportation, Federal Highway Administration For sale by the Supt. of Docs., U.S. G.P.O, 1989.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)United States. Federal Highway Administration. Manual on Uniform Traffic Control Devices: For Streets and Highways. 1988 ed. U.S. Dept. of Transportation, Federal Highway Administration For sale by the Supt. of Docs., U.S. G.P.O, 1989.