1. Graphs and their chromatic numbers;Behzad,1955
2. The color number of complete graphs;Behzad;J. London Math. Soc.,1967
3. Graph Theory;Harary,1969
4. Färburgsprobleme auf Flächen und Graphen;Ringel,1959
5. On the total coloring of certain graphs;Rosenfeld;Isr. J. Math.,1971