1. National Space-Based Positioning, Navigation and Timing Coordination Office. Global Positioning System, GPS. Retrieved June 6, 2010

http://www.gps.gov/index.html

2. GPS world, business and technology of GPS. Article: GPS modernization and new policy for GPS by Jeffery N. Shane, March 1st, 2005. Retrieved May, 19, 2010

http://www.gpsworld.com/gnss-system/gps-modernization/a-new-policy-gps-945

3, 4. How GPS receiver works? Retrieved May 19, 2010

http://electronics.howstuffworks.com/gadgets/travel/gps.htm

5. Global Positioning System GPS, Timing. Retrieved May 19, 2010

http://www.gps.gov/applications/timing/index.html

6. Global Positioning System GPS, Roads and Highways. Retrieved May 19, 2010 http://www.gps.gov/applications/roads/index.html

7. Global Positioning System GPS, Aviation. Retrieved May 19, 2010

http://www.gps.gov/applications/aviation/index.html

8. Global Positioning System GPS, Marine. Retrieved May 19, 2010

http://www.gps.gov/applications/marine/index.html

9. Global Positioning System GPS, Public safety. Retrieved May 19, 2010

http://www.gps.gov/applications/safety/index.html

10. National Academy of Science, Beyond Discovery. GPS and the Future. (article written by MIT scientist Daniel Kleppner for Beyond Discovery TM: The Path from Research to Human Benefit) Retrieved May 19, 2010

http://www.beyonddiscovery.org/content/view.page.asp?I=468

image GPS device on introduction page is obtained from garmin.com (retrieved 6/8/2010)

image GPS satellite on How gps works page is obtained from aero.org (retrieved 6/9/2010)

Additional information

Global Positioning System. (2010,). Wikipedia, the free encyclopedia. Retrieved May 19, 2010

http://en.wikipedia.org/wiki/Global_Positioning_System