Norton, H. S. (1963). Modern transportation economics. Merrill Books.
Cita Chicago (17th ed.)Norton, Hugh Stanton. Modern Transportation Economics. Columbus, Ohio: Merrill Books, 1963.
Cita MLA (9th ed.)Norton, Hugh Stanton. Modern Transportation Economics. Merrill Books, 1963.
Atenció: Aquestes cites poden no estar 100% correctes.