Dong, F. M., Gordon Royle, and Dave Wagner. “Chromatic Roots of a Ring of Four Cliques”. The Electronic Journal of Combinatorics 18, no. 1 (July 22, 2011): P151. Accessed March 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v18i1p151.