Gorr, W. L. (2007). Learning and using geographic information systems: ArcGIS edition. Boston, MA: Thomson Course Technology.
Παραπομπή Chicago StyleGorr, Wilpen L. Learning and Using Geographic Information Systems: ArcGIS Edition. Boston, MA: Thomson Course Technology, 2007.
Παραπομπή MLAGorr, Wilpen L. Learning and Using Geographic Information Systems: ArcGIS Edition. Boston, MA: Thomson Course Technology, 2007.
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