== References ==== Additional reading ==* Victor Klee and Stan Wagon, "Old and New Unsolved Problems in Plane Geometry and Number Theory", The Dolciani Mathematical Expositions, Number 11, Mathematical Association of America, 1991== External links ==* Mark J. Nielsen, Figures Inscribed in Curves.
* Victor Klee and Stan Wagon, "Old and New Unsolved Problems in Plane Geometry and Number Theory", The Dolciani Mathematical Expositions, Number 11, Mathematical Association of America, 1991* Mark J. Nielsen, Figures Inscribed in Curves.