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.
Παραπομπή σε μορφή Chicago (17η εκδ.)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, και Wagdy G. Wassef. Integral Steel Box-beam Pier Caps. Washington, D.C: Transportation Research Board, 2004.
Παραπομπή σε μορφή MLA (9th εκδ.)National Cooperative Highway Research Program, et al. Integral Steel Box-beam Pier Caps. Transportation Research Board, 2004.