Brouwer, Andries. “The Equivalence of Two Inequalities for Quasisymmetric Designs”. The Electronic Journal of Combinatorics 30, no. 1 (February 10, 2023): P1.22. Accessed March 29, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v30i1p22.