Haas, Wolfgang, Immanuel Halupczok, and Jan-Christoph Schlage-Puchta. “Lower Bounds for $q$-Ary Codes With Large Covering Radius”. The Electronic Journal of Combinatorics 16, no. 1 (November 7, 2009): R133. Accessed March 16, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v16i1r133.