National Research Council (U.S.). Highway Research Board. Committee on Communications & National Research Council (U.S.). Highway Research Board. Committee on Motorist Services. (1971). Communications and emergency services: 6 reports. Highway Research Board, National Research Council.
Chicago-referens (17:e uppl.)National Research Council (U.S.). Highway Research Board. Committee on Communications och National Research Council (U.S.). Highway Research Board. Committee on Motorist Services. Communications and Emergency Services: 6 Reports. Washington, D.C: Highway Research Board, National Research Council, 1971.
MLA-referens (9:e uppl.)National Research Council (U.S.). Highway Research Board. Committee on Communications och National Research Council (U.S.). Highway Research Board. Committee on Motorist Services. Communications and Emergency Services: 6 Reports. Highway Research Board, National Research Council, 1971.