Council, National Research; Studies, Division on Earth and Life; Resources, Board on Earth Sciences and; Committee, Geographical Sciences; Curriculum, Committee on Support for Thinking Spatially: The Incorporation of Geographic Information Science Across the K.-12 (3 February 2005). Learning to Think Spatially. National Academies Press. p.157. ISBN978-0-309-09208-1.{{cite book}}: CS1 maint: numeric names: authors list (link)