Original by Andreas Wahra, new version by Till Niermann published on 26 April 2012
Based on Wikipedia content that has been reviewed, edited, and republished.
Original image by Original by Andreas Wahra, new version by Till Niermann. Uploaded by Jan van der Crabben, published on 26 April 2012 under the following license: Creative Commons: Attribution-ShareAlike. This license lets others remix, tweak, and build upon your work even for commercial reasons, as long as they credit you and license their new creations under the identical terms.