English: Optimal circle packing (for the circles in circle problem, case n=12): Proved optimal by Fodor in 2000. Beiträge zur Algebra und Geometrie, Contributions to Algebra and Geometry 41 (2000) 401-409
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.