National Cooperative Highway Research Program, National Research Council (U.S.). Transportation Research Board, & Potts, I. B. (2004). Safety of U-turns at unsignalized median openings. Transportation Research Board.
Chicago-referens (17:e uppl.)National Cooperative Highway Research Program, National Research Council (U.S.). Transportation Research Board, och Ingrid B. Potts. Safety of U-turns at Unsignalized Median Openings. Washington, D.C: Transportation Research Board, 2004.
MLA-referens (9:e uppl.)National Cooperative Highway Research Program, et al. Safety of U-turns at Unsignalized Median Openings. Transportation Research Board, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.