1. Maximum-Minimum Sätze und verallgemeinerte Faktoren von Graphen;Gallai;Acta Math. Acad. Sci. Hungar.,1961
2. F. Harary, S. Hedetiemi, and G. Prins, An Interpolation Theorem for Graphical Homomorphisms, Portugal. Math., to appear.
3. On Complementary Graphs;Nordhaus;Amer. Math. Monthly,1956
4. Theory of Graphs;Ore,1962