Hill, F. G. (1957). Roads, rails and waterways: The army engineers and early transportation. Norman: University of Oklahoma Press.
Παραπομπή Chicago StyleHill, Forest G. Roads, Rails and Waterways: The Army Engineers and Early Transportation. Norman: University of Oklahoma Press, 1957.
Παραπομπή MLAHill, Forest G. Roads, Rails and Waterways: The Army Engineers and Early Transportation. Norman: University of Oklahoma Press, 1957.
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