Ito, Hisashi, Akiko Kato, Zsigmond Nagy, and Kenneth Zeger. “Zero Capacity Region of Multidimensional Run Length Constraints”. The Electronic Journal of Combinatorics 6, no. 1 (September 1, 1999): R33. Accessed March 28, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v6i1r33.