National Cooperative Highway Research Program, National Research Council (U.S.). Transportation Research Board, American Association of State Highway and Transportation Officials, United States. Federal Highway Administration, & Wassef, W. G. (2004). Integral steel box-beam pier caps. Transportation Research Board.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Cooperative Highway Research Program, National Research Council (U.S.). Transportation Research Board, American Association of State Highway and Transportation Officials, United States. Federal Highway Administration, و Wagdy G. Wassef. Integral Steel Box-beam Pier Caps. Washington, D.C: Transportation Research Board, 2004.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)National Cooperative Highway Research Program, et al. Integral Steel Box-beam Pier Caps. Transportation Research Board, 2004.