1. I. Bárány, The densest (nRn, 63, Intuitive Geometry, Coll. Math. Soc. János Bólyai, Szeged, Hungary, 1991, 7, 10
2. K. Bezdek, R. Connelly, The minimum diameter ofdd, 1, 8, 1997
3. Geometrical extrema suggested by a lemma of Besicovitch;Bateman;Amer. Math. Monthly,1951
4. Über eine Extremaleigenschaft des Kreises;Bieberbach;Jahresber. d. D. M.-V.,1915
5. The decomposition of then;Larman;Ann. Disc. Math.,1984