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.
Chicago-referens (17:e uppl.)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.
MLA-referens (9:e uppl.)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.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.