Bailey, Robert F., and Daniel R. Hawtin. “On the 486-Vertex Distance-Regular Graphs of Koolen-Riebeek and Soicher”. The Electronic Journal of Combinatorics 27, no. 3 (July 24, 2020): P3.13. Accessed March 27, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v27i3p13.