1. A triangle-free circle graph with chromatic number 5;Ageev;Discrete Math.,1996
2. Covering and coloring problems for relatives of intervals;Gyárfás;Discrete Math.,1985
3. Graph Coloring Problems;Jensen,1995
4. On perfect arc and chord intersection graphs;Karapetyan,1984
5. On upper bounds for the chromatic numbers of graphs;Kostochka;Trudy Inst. Mat.,1988