Lewis, D. L. (1991). Primer on transportation, productivity, and economic development. Transportation Research Board, National Research Council.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रLewis, David L. Primer on Transportation, Productivity, and Economic Development. Washington, D.C: Transportation Research Board, National Research Council, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रLewis, David L. Primer on Transportation, Productivity, and Economic Development. Transportation Research Board, National Research Council, 1991.
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