Nichols, H. L. 1., Day, D. A., & Day, D. A. (1999). Moving the earth: The workbook of excavation (4th ed.). New York: McGraw-Hill.
Παραπομπή Chicago StyleNichols, Herbert L. 1908-, David A. Day, and David A. Day. Moving the Earth: The Workbook of Excavation. 4th ed. New York: McGraw-Hill, 1999.
Παραπομπή MLANichols, Herbert L. 1908-, David A. Day, and David A. Day. Moving the Earth: The Workbook of Excavation. 4th ed. New York: McGraw-Hill, 1999.
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