Claude A. Christen, Stanley M. Selkow. Some perfect coloring properties of graphs. Journal of Combinatorial Theory, Series A, 27(1):49-59, 1979. [doi]
@article{ChristenS79, title = {Some perfect coloring properties of graphs}, author = {Claude A. Christen and Stanley M. Selkow}, year = {1979}, doi = {10.1016/0095-8956(79)90067-4}, url = {http://dx.doi.org/10.1016/0095-8956(79)90067-4}, tags = {graph-rewriting, rewriting}, researchr = {https://researchr.org/publication/ChristenS79}, cites = {0}, citedby = {0}, journal = {Journal of Combinatorial Theory, Series A}, volume = {27}, number = {1}, pages = {49-59}, }