Min Wan, Baogang Xu. Cyclic 9-coloring of plane graphs with maximum face degree six. Ars Comb., 121:413-420, 2015.
@article{WanX15-2, title = {Cyclic 9-coloring of plane graphs with maximum face degree six}, author = {Min Wan and Baogang Xu}, year = {2015}, researchr = {https://researchr.org/publication/WanX15-2}, cites = {0}, citedby = {0}, journal = {Ars Comb.}, volume = {121}, pages = {413-420}, }