Não informado. (1990). Cartography and geographic information systems. American Congress on Surveying and Mapping.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Cartography and Geographic Information Systems. Bethesda, Md: American Congress on Surveying and Mapping, 1990.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Cartography and Geographic Information Systems. American Congress on Surveying and Mapping, 1990.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.