http://www.lemonde.fr/culture/visuel/2013/11/01/sur-les-traces-de-banksy-a-new-york_3507086_3246.html
http://people.southwestern.edu/~bednarb/su_netWorks/projects/jle/balloon.html
http://people.southwestern.edu/~bednarb/su_netWorks/projects/jle/balloon.html