De Bruyn, Bart, and Pieter Vandecasteele. “The Valuations of the Near Octagon ${\Bbb I}_4$”. The Electronic Journal of Combinatorics 13, no. 1 (August 25, 2006): #R76. Accessed April 12, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v13i1r76.