几何数论alia. Gardner对星形集和非凸集取得了一些成果。 Schmidt's books. Grötschel et alia, Lovász et alia, Lovász. Matthias Beck, Sinai Robins. Computing the continuous discretely:
图子式of the Hadwiger number of graphs by their average degree, Combinatorica, 1984, 4: 307–316, doi:10.1007/BF02579141 (英语) . Lovász, László, Graph minor