Eyal Ackerman, Kevin Buchin, Christian Knauer, Rom Pinchasi, Günter Rote. There are not too many magic configurations. In Jeff Erickson, editor, Proceedings of the 23rd ACM Symposium on Computational Geometry, Gyeongju, South Korea, June 6-8, 2007. pages 142-149, ACM, 2007. [doi]
Abstract is missing.