WRIGHT, P. H., & ASHFORD, N. J. (1989). Tranportation engineering: Planning and design.--Ed.3. John Wiley and Sons.
Cita Chicago (17th ed.)WRIGHT, Paul H., i Norman J. ASHFORD. Tranportation Engineering: Planning and Design.--Ed.3. New York: John Wiley and Sons, 1989.
Cita MLA (9th ed.)WRIGHT, Paul H., i Norman J. ASHFORD. Tranportation Engineering: Planning and Design.--Ed.3. John Wiley and Sons, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.