Board, N. R. C. T. R. (1987). Private sector involvement and toll road financing in the provision of highways. Washington, DC : Transportation Research Board.
Dyfyniad Arddull ChicagoBoard, National Research Council. Transportation Research. Private Sector Involvement and Toll Road Financing in the Provision of Highways. Washington, DC : Transportation Research Board, 1987.
Dyfyniad MLABoard, National Research Council. Transportation Research. Private Sector Involvement and Toll Road Financing in the Provision of Highways. Washington, DC : Transportation Research Board, 1987.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.