http://www.exploratorium.edu

http://www.sciam.com

http://www.nelsonthornes.com/STOIC/secondary/science/scinet/scinet/light/refrac/content.htm

http://www.nature.com

http://www.acornnaturalists.com

http://tryscience.org

http://riker.ps.missouri.edu/rickspage/refract/refraction.html

http://casa.colorado.edu/~ajsh/distort1big_gif.html

http://www.alphalink.com.au/~vmck/rmain.htm

http://www.gelighting.com/na/home/gela/students/science_bending.htm