National Research Council (U.S.). Transportation Research Board. (1988). Research problem statements on traffic control devices. Transportation Research Board, National Research Council.
Chicago-Zitierstil (17. Ausg.)National Research Council (U.S.). Transportation Research Board. Research Problem Statements on Traffic Control Devices. Washington, D.C: Transportation Research Board, National Research Council, 1988.
MLA-Zitierstil (9. Ausg.)National Research Council (U.S.). Transportation Research Board. Research Problem Statements on Traffic Control Devices. Transportation Research Board, National Research Council, 1988.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.