Dyfyniad APA

Ingram, G. K., & Liu, Z. (1998). Vehicles, roads, and road use: Alternative empirical specifications. World Bank.

Dyfyniad Arddull Chicago

Ingram, Gregory K., and Zhi Liu. Vehicles, Roads, and Road Use: Alternative Empirical Specifications. Washington, D.C: World Bank, 1998.

Dyfyniad MLA

Ingram, Gregory K., and Zhi Liu. Vehicles, Roads, and Road Use: Alternative Empirical Specifications. World Bank, 1998.

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