Não informado. (1990). Cartography and geographic information systems. American Congress on Surveying and Mapping.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Cartography and Geographic Information Systems. Bethesda, Md: American Congress on Surveying and Mapping, 1990.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Cartography and Geographic Information Systems. American Congress on Surveying and Mapping, 1990.
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