Collins, Karen L., and Ann Trenk. “Nordhaus-Gaddum Theorem for the Distinguishing Chromatic Number”. The Electronic Journal of Combinatorics 20, no. 3 (September 26, 2013): P46. Accessed March 15, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v20i3p46.