1. Congressional Subcommittee. (1999). Congressional Hearing. Geographical information systems policies and program, June 9, 1999. Subcommittee on Government Management, Information, and Technology (Stephen Horn, Chairman). Retrieved September 20, 2004, from http://www.house.gov/reform/gmit/hearings/testimony/990609h.htm. See also, National Research Council (NRC). (2003). IT roadmap to a geospatial future. Committee on Intersections between geospatial information and information technology. Washington, DC: National Academies Press; and Martinex-Asenjo, B., & Frank, A. U. (2001). The transformation of NMAs from government departments to independent organizations: An economic overview. In Proceedings of AGILE 2001, Brno, Czech Republic. Retrieved October 12, 2001, from ftp.geoinfo.tuwein.ac.at/martinez/brno2001/martinez_asenjo.pdf
2. Mapping Science Committee. (1999). Distributed geolibraries: Spatial information resources. Summary of a workshop: Panel on distributed geolibraries, mapping science committee (National Research Council [US]). Washington, DC: National Academy Press. Retrieved February 10, 2002, from http://www.nap.edu/html/geolibraries/
3. FGDC: Federal Geographic Data Committee. Retrieved from http://www.fgdc.gov
4. New horizons for the social sciences: Geographical information systems;Goodchild;Canadian Journal of Policy Research,2000
5. Cartographic perspectives on a digital future;Goodchild;Cartographic Perspectives,2000