De Winter S, Lazebnik F, Verstraëte J. An Extremal Characterization of Projective Planes. Electron. J. Combin. [Internet]. 2008Nov.30 [cited 2026Apr.12];15(1):#R143. Available from: https://www.combinatorics.org/ojs/index.php/eljc/article/view/v15i1r143