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.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিUnited 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.
M.L.A (9 ম সংস্করণ) উদ্ধৃতিUnited 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.