1. WHO: Magnitude and causes of Visual Impairment. Fact sheet no. 282 (November 2004)
2. Allaart, P.C., Kawamura, K.: Dimensions of the coordinate functions of space-filling curves. Journal of Mathematical Analysis and Applications 335, 1161–1176 (2007)
3. Wu, Z., Huang, N.E.: Ensemble empirical mode decomposition: a noise-assisted data analysis method. Centre for Ocean-Land-Atmosphere Studies, Calverton, Md, USA (2005)
4. GPS,
http://www.senderogroup.com
(last viewed on Janury 2011)
5. StreetTalk,
http://www.freedomscientific.com
(last viewed on January 2011)