Edge-face coloring of plane graphs with maximum degree nine
An edge-face coloring of a plane graph with edge set E and face set F is a coloring of the elements of E?F so that adjacent or incident elements receive different colors. Borodin [Discrete Math 128(13):2133, 1994] proved that every plane graph of maximum degree ??10 can be edge-face colored with ? + 1 colors. We extend Borodin's result to the case where ? = 9.  2010 Wiley Periodicals, Inc. J Graph Theory 66:332-346, 2011
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