Ford, R. E. (1999). GeoSystems today: An interactive casebook. New York: John Wiley & Sons.
Trích dẫn kiểu ChicagoFord, Robert E. GeoSystems Today: An Interactive Casebook. New York: John Wiley & Sons, 1999.
Deismireacht MLAFord, Robert E. GeoSystems Today: An Interactive Casebook. New York: John Wiley & Sons, 1999.
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