National Research Council (U.S.). Transportation Research Board & National Research Council (U.S.). Transportation Research Board. Meeting. (2004). Travel behavior and values, 2004. Transportation Research Board.
Dyfyniad Arddull ChicagoNational Research Council (U.S.). Transportation Research Board and National Research Council (U.S.). Transportation Research Board. Meeting. Travel Behavior and Values, 2004. Washington, D.C: Transportation Research Board, 2004.
Dyfyniad MLANational Research Council (U.S.). Transportation Research Board and National Research Council (U.S.). Transportation Research Board. Meeting. Travel Behavior and Values, 2004. Transportation Research Board, 2004.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.