National Research Council (U.S.). Highway Research Board. (1969). Freeway traffic characteristics and control: 19 reports. Highway Research Board, National Research Council.
Dyfyniad Arddull ChicagoNational Research Council (U.S.). Highway Research Board. Freeway Traffic Characteristics and Control: 19 Reports. Washington, D.C: Highway Research Board, National Research Council, 1969.
Dyfyniad MLANational Research Council (U.S.). Highway Research Board. Freeway Traffic Characteristics and Control: 19 Reports. Highway Research Board, National Research Council, 1969.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.