DeMERS, M. N. (1997). Fundamentals of geographic information systems. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)DeMERS, Michael N. Fundamentals of Geographic Information Systems. New York: John Wiley and Sons, 1997.
Lua MLA (9ú heag.)DeMERS, Michael N. Fundamentals of Geographic Information Systems. John Wiley and Sons, 1997.
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