1. Cook M.: In: Moore, C., Griffeath, D. (eds) New Constructions in Cellular Automata, Volume 226, pp. 93–118. Oxford University Press, Oxford (2003)
2. Cornuéjols G.: General factors of graphs. J. Comb. Theory Ser. B 45, 185–198 (1988)
3. de Berg, M., Khosravi, A.: Optimal binary space partitions in the plane. In: Proceeding of 16th International Computing and Combinatorics Conference (COCOON’2010), vol. 6196 of LNCS, pp. 216–225. Springer, Berlin (2010)
4. Edmonds, J.: Submodular functions, matroids, and certain polyhedra. In: Proceedings of the Calgary International Conference on Combinatorial Structures and Their Applications, pp. 69–87. Calgary (1969)
5. Garey M.R., Johnson D.: Computers and Intractability: A Guide to the Theory of NP-Completeness. W.H. Freeman, San Francisco (1979)