Grinberg, Darij, and Benjamin Liber. “An Equality for Balanced Digraphs”. The Electronic Journal of Combinatorics 33, no. 3 (July 17, 2026): #P3.19. Accessed July 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v33i3p19.