Nagel, Uwe, and Victor Reiner. “Betti Numbers of Monomial Ideals and Shifted Skew Shapes”. The Electronic Journal of Combinatorics 16, no. 2 (February 11, 2009): R3. Accessed April 4, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v16i2r3.