http://www.coolopticalillusions.com/eye-tricks/optic-pictures/moire_circle.gif
― lxy, Monday, 7 April 2008 06:18 (sixteen years ago) link
http://files.meetup.com/227762/Circle%20of%20Fifths%20wheel.gif
http://www.apa.org/ed/circle.gif
― lxy, Monday, 7 April 2008 06:19 (sixteen years ago) link
http://static.guim.co.uk/sys-images/Arts/Arts_/Pictures/2008/12/16/bharti460.jpg
― lxy, Friday, 26 December 2008 17:07 (fifteen years ago) link