Boll, David W., Jerry Donovan, Ronald L. Graham, and Boris D. Lubachevsky. “Improving Dense Packings of Equal Disks in a Square”. The Electronic Journal of Combinatorics 7, no. 1 (August 1, 2000): R46. Accessed March 16, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v7i1r46.