Lewis, D. L. (1991). Primer on transportation, productivity, and economic development. Transportation Research Board, National Research Council.
Chicago-Zitierstil (17. Ausg.)Lewis, David L. Primer on Transportation, Productivity, and Economic Development. Washington, D.C: Transportation Research Board, National Research Council, 1991.
MLA-Zitierstil (9. Ausg.)Lewis, David L. Primer on Transportation, Productivity, and Economic Development. Transportation Research Board, National Research Council, 1991.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.