(1996). Manual on GIS for planners and decision makers. United Nations.
Cita Chicago (17th ed.)Manual on GIS for Planners and Decision Makers. New York: United Nations, 1996.
Cita MLA (8th ed.)Manual on GIS for Planners and Decision Makers. United Nations, 1996.
Atenció: Aquestes cites poden no estar 100% correctes.