Brinker, R. C. & Wolf, P. R. (1984). Elementary surveying (7th ed.). New York: Harper and Row. Dana, P. H. (1998). Global positioning system overview. The geographer's craft project. Retrieved August 2, 1999, from http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html
Doyle, D. R. (1994). Development of the National Spatial Reference System. Retrieved Feburary 10, 2008, from http://www.ngs.noaa.gov/PUBS_LIB/develop_NSRS.html
Federal Geodetic Control Committee (1988). Geometric geodetic accuracy standards and specifications for using GPS relative positioning techniques. Retrieved February 10, 2008, from http://www.ngs.noaa.gov/FGCS/tech_pub/GeomGeod.pdf
Hall, G. W. (1996). USCG differential GPS navigation service. Retrieved November 9, 2005, from http://www.navcen.uscg.gov/pdf/dgps/dgpsdoc.pdf
Hodgson, C. V. Measuring base with invar tape. Tape underway. Base line and astro party, ca. 1916. NOAA Historical Photo Collection (2004). Retrieved on April 20, 2006, from http://www.photolib.noaa.gov/
Hurn, J. (1989). GPS: A guide to the next utility. Sunnyvale CA: Trimble Navigation Ltd.
Hurn, J. (1993). Differential GPS Explained. Sunnyvale CA: Trimble Navigation Ltd.
mobiThinking (2012, June). Global mobile statistics 2012 Part A: Mobile subscribers; handset market share; mobile operators. Retrieved August 5, 2012, from http://mobithinking.com/mobile-marketing-tools/latest-mobile-stats/a#subscribers
mobiThinking (2012, June). Global mobile statistics 2012 Part D: Consumer mobile behavior. Retrieved August 5, 2012, from http://mobithinking.com/mobile-marketing-tools/latest-mobile-stats/d#mobilebehavior
Monmonier, M. (1995). Boundary litigation and the map as evidence. In Drawing the Line: Tales of Maps and Cartocontroversy. New York: Henry Holt.
National Geodetic Survey (n. d.). Retrieved November 4, 2009, from http://www.ngs.noaa.gov
National Geodetic Survey (n.d.). National Geodetic Survey - CORS, Continuously Operating Reference Stations. Retrieved August 2, 1999, from http://www.ngs.noaa.gov/CORS/cors-data.html
NAVSTAR GPS Joint Program Office. Retrieved October 21, 2000, from http://gps.losangeles.af.mil/
Norse, E. T. (2004). Tracking new signals from space - GPS modernization and Trimble R-Track Technology. Retrieved November 9, 2005, from http://www.trimble.com/survey_wp_gpssys.asp?Nav=Collection-27596
Raisz, E. (1948). McGraw-Hill series in geography: General cartography (2nd ed.). York, PA: The Maple Press Company.
Robinson, A. et al. (1995). Elements of cartography (5th ed.). New York: John Wiley & Sons.
Smithsonian National Air and Space Museum (1998). GPS: A new constellation. Retrieved August 2, 1999, from http://www.nasm.si.edu/gps/
Snay, R. (2005, September 13). CORS users forum--towards real-time positioning. Power point presentation presented at the 2005 CORS Users Forum, Long Beach, CA. Presentation retrieved October 26, 2005, from http://www.ngs.noaa.gov/CORS/Presentations/CORSForum2005/Richard_Snay_Forum2005.pdf
Thompson, M. M. (1988). Maps for America, cartographic products of the U.S. Geological Survey and others (3d ed.). Reston, Va.: U.S. Geological Survey.
U.S. Coast Guard Navigation Center (n .d.). DGPS general information. Retrieved February 10, 2008, from http://www.navcen.uscg.gov/?pageName=dgpsMainwww.navcen.uscg.gov/
U.S. Federal Aviation Administration (2007a). Frequently asked questions. Retrieved February 10, 2008, from http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/faq/gps/
U.S. Federal Aviation Administration (2007b). Global Positioning System: How it works. Retrieved February 10, 2008, from http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/gps/howitworks/
U.S. Federal Aviation Administration. (2007c). Wide Area Augmentation System. Retrieved Feburary 10, 2008, from http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/gps/howitworks/
Van Sickle, J. (2001). GPS for land surveyors. New York: Taylor and Francis.
Van Sickle, J. (2004). Basic GIS coordinates. Boca Raton: CRC Press.
Wolf, P. R. & Brinker, R. C. (1994). Elementary surveying (9th ed.). NY, NY: HarperCollins College Publisher.
Wormley, S. (2006). GPS errors and estimating your receiver's accuracy. Retrieved April 20, 2006, from http://www.edu-observatory.org/gps/gps_accuracy.html
Yeazel, J. (2006). WAAS and its relation to enabled hand-held GPS receivers. Retrieved October 12, 2005, from http://gpsinformation.net/exe/waas.html