1. Simulated Annealing and Boltzmann Machines;Aarts,1989
2. Sets of points with given maximum separation (Problem E1921);Coxeter;Amer. Math. Monthly,1968
3. Unsolved Problems in Geometry;Croft,1991
4. Solid circle-packings and circle-coverings;Fejes Tóth;Studia Sci. Math. Hungar.,1968
5. Lagerungen in der Ebene, auf der Kugel und im Raum;Fejes Tóth,1972