National Research Council (U.S.). Transportation Research Board. (1990). Research problem statements: Operation, safety and maintenance of transportation facilities. Transportation Research Board, National Research Council.
Trích dẫn kiểu Chicago (xuất bản lần thứ 7)National Research Council (U.S.). Transportation Research Board. Research Problem Statements: Operation, Safety and Maintenance of Transportation Facilities. Washington, D.C: Transportation Research Board, National Research Council, 1990.
Trích dẫn kiểu MLA (xuất bản lần thứ 9)National Research Council (U.S.). Transportation Research Board. Research Problem Statements: Operation, Safety and Maintenance of Transportation Facilities. Transportation Research Board, National Research Council, 1990.
Cảnh báo: Các trích dẫn này có thể không phải lúc nào cũng chính xác 100%.