Dujmović, Vida, Fabrizio Frati, Gwenaël Joret, and David R. Wood. “Nonrepetitive Colourings of Planar Graphs With $O(\log n)$ Colours”. The Electronic Journal of Combinatorics 20, no. 1 (March 1, 2013): P51. Accessed April 7, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v20i1p51.