National Research Council (U.S.). Highway Research Board. (1973). Freeway operational improvements. National Academy of Science - National Research Council.
Chicago-referens (17:e uppl.)National Research Council (U.S.). Highway Research Board. Freeway Operational Improvements. Washington, D.C: National Academy of Science - National Research Council, 1973.
MLA-referens (9:e uppl.)National Research Council (U.S.). Highway Research Board. Freeway Operational Improvements. National Academy of Science - National Research Council, 1973.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.