Bibliografia/Sitografia
  1. M.N. DEMERS, "Fundamentals of Geographic Information Systems". J.Wiley&Sons. 1997
  2. R. LAURINI, D. THOMPSON, "Fundamentals of Spatial Information Systems". Academic Press. 1992
  3. M.F. WORBOYS, "GIS: a computing perspective". Taylor&Francis. 1995
  4. P. BURROUGH, "Principles of Geographic Information Systems". Oxford University Press. 1998