Calender_process.  Visualization of the calender process. April 2007. Laurens van Lieshout.
No machine-readable author provided. <a href="//commons.wikimedia.org/wiki/User:LaurensvanLieshout" title="User:LaurensvanLieshout">LaurensvanLieshout</a> assumed (based on copyright claims).
No machine-readable source provided. Own work assumed (based on copyright claims).