National Research Council (U.S.). Highway Research Board. (1973). Environmental considerations in planning, design, and construction. Highway Research Board.
Dyfyniad Arddull ChicagoNational Research Council (U.S.). Highway Research Board. Environmental Considerations in Planning, Design, and Construction. Washington: Highway Research Board, 1973.
Dyfyniad MLANational Research Council (U.S.). Highway Research Board. Environmental Considerations in Planning, Design, and Construction. Highway Research Board, 1973.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.