1. PlaneCrashInfo.com, Accident statistics (August 28, 2014),
http://www.planecrashinfo.com/cause.htm
2. Kulesa, G.: Weather and aviation: How does weather affect the safety and operations of airports and aviation, and how does FAA work to manage weather-related effects? In: The Potential Impacts of Climate Change on Transportation (2003)
3. Clynch, J.R.: GPS Accuracy Levels. (2001),
http://www.oc.nps.edu/oc2902w/gps/gpsacc.html
(October 15, 2014)
4. Belabbas, B., Hornbostel, A., Sadeque, M.Z.: Error analysis of single frequency gps measurements and impact on timing and positioning accuracy (2005)
5. Fox, K.C.: Impacts of Strong Solar Flares. (2013),
http://www.nasa.gov/mission_pages/sunearth/news/flare-impacts.html
(October 15, 2014)