Chee, Yeow Meng. “Steiner Triple Systems Intersecting in Pairwise Disjoint Blocks”. The Electronic Journal of Combinatorics 11, no. 1 (April 2, 2004): R27. Accessed March 17, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v11i1r27.