Cita APA (7th ed.)
Hay, W. W. (1961). An introduction to transportation engineering. Wiley.
Cita Chicago (17th ed.)
Hay, William Walter. An Introduction to Transportation Engineering. New York: Wiley, 1961.
Cita MLA (9th ed.)
Hay, William Walter. An Introduction to Transportation Engineering. Wiley, 1961.
Atenció: Aquestes cites poden no estar 100% correctes.