Gutowski, Grzegorz, Ming Han, Tomasz Krawczyk, and Xuding Zhu. “Defective 3-Paintability of Planar Graphs”. The Electronic Journal of Combinatorics 25, no. 2 (May 25, 2018): P2.34. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v25i2p34.