Dehkordi, Hooman R., and Graham Farr. “Non-Separating Planar Graphs”. The Electronic Journal of Combinatorics 28, no. 1 (January 15, 2021): P1.11. Accessed March 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v28i1p11.