National Research Council (U.S.). Transportation Research Board & National Cooperative Highway Research Program. (2001). Continuing project to synthesize information on highway problems. Transportation Research Board, National Research Council.
Chicago-referens (17:e uppl.)National Research Council (U.S.). Transportation Research Board och National Cooperative Highway Research Program. Continuing Project to Synthesize Information on Highway Problems. Washington, D.C: Transportation Research Board, National Research Council, 2001.
MLA-referens (9:e uppl.)National Research Council (U.S.). Transportation Research Board och National Cooperative Highway Research Program. Continuing Project to Synthesize Information on Highway Problems. Transportation Research Board, National Research Council, 2001.