Cita APA (7th ed.)

Witheford, D. K., & Cunagin, W. D. (1992). Truck escape ramps. Transportation Research Board, National Research Council.

Cita Chicago (17th ed.)

Witheford, David K., i Wiley D. Cunagin. Truck Escape Ramps. Washington, DC: Transportation Research Board, National Research Council, 1992.

Cita MLA (9th ed.)

Witheford, David K., i Wiley D. Cunagin. Truck Escape Ramps. Transportation Research Board, National Research Council, 1992.