Cioabă, Sebastian M. “Bounds on the Turán Density of ${\rm PG}(3,2)$”. The Electronic Journal of Combinatorics 11, no. 1 (March 5, 2004): N3. Accessed April 5, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v11i1n3.