Lagoutte, Aurélie. “Coloring Graphs With No Even Hole of Length at Least 6: The Triangle-Free Case”. The Electronic Journal of Combinatorics 24, no. 3 (July 14, 2017): #P3.8. Accessed May 16, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v24i3p8.