Dyfyniad APA

National Research Council (U.S.). Transportation Research Board. (1992). Railroad issues. Transportation Research Board, National Research Council.

Dyfyniad Arddull Chicago

National Research Council (U.S.). Transportation Research Board. Railroad Issues. Washington, D.C: Transportation Research Board, National Research Council, 1992.

Dyfyniad MLA

National Research Council (U.S.). Transportation Research Board. Railroad Issues. Transportation Research Board, National Research Council, 1992.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.