Dyfyniad APA

National Research Council (U.S.). Transportation Research Board. Committee A3B05. (1990). Travelers' services: Research problem statements. Transportation Research Board, National Research Council.

Dyfyniad Arddull Chicago

National Research Council (U.S.). Transportation Research Board. Committee A3B05. Travelers' Services: Research Problem Statements. Washington, DC: Transportation Research Board, National Research Council, 1990.

Dyfyniad MLA

National Research Council (U.S.). Transportation Research Board. Committee A3B05. Travelers' Services: Research Problem Statements. Transportation Research Board, National Research Council, 1990.

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