National Research Council (U.S.). Transportation Research Board. (1979). Local rail services program: Perspectives of states and railroads. Transportation Research Board, National Academy of Sciences.
Dyfyniad Arddull ChicagoNational Research Council (U.S.). Transportation Research Board. Local Rail Services Program: Perspectives of States and Railroads. Washington, D.C: Transportation Research Board, National Academy of Sciences, 1979.
Dyfyniad MLANational Research Council (U.S.). Transportation Research Board. Local Rail Services Program: Perspectives of States and Railroads. Transportation Research Board, National Academy of Sciences, 1979.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.