Hetherington, Timothy J., and Douglas R. Woodall. “Edge and Total Choosability of Near-Outerplanar Graphs”. The Electronic Journal of Combinatorics 13, no. 1 (October 31, 2006): #R98. Accessed April 12, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v13i1r98.