National Research Council (U.S.). Transportation Research Board & National Research Council (U.S.). Transportation Research Board. Meeting. (2006). Traffic control devices, visibility, and rail-highway grade crossings, 2006. Transportation Research Board.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Research Council (U.S.). Transportation Research Board و National Research Council (U.S.). Transportation Research Board. Meeting. Traffic Control Devices, Visibility, and Rail-highway Grade Crossings, 2006. Washington, D.C: Transportation Research Board, 2006.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)National Research Council (U.S.). Transportation Research Board و National Research Council (U.S.). Transportation Research Board. Meeting. Traffic Control Devices, Visibility, and Rail-highway Grade Crossings, 2006. Transportation Research Board, 2006.