Παραπομπή σε μορφή APA (7η εκδ.)

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.

Παραπομπή σε μορφή Chicago (17η εκδ.)

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.

Παραπομπή σε μορφή MLA (9th εκδ.)

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.