de Fraysseix, Hubert, and Patrice Ossona de Mendez. “Connectivity of Planar Graphs”. Journal of Graph Algorithms and Applications 5, no. 5 (January 1, 2001): 93–105. Accessed December 7, 2025. https://jgaa-v5.cs.brown.edu/index.php/jgaa/article/view/paper41.