Drube, Paul. “Generating Functions for Inverted Semistandard Young Tableaux and Generalized Ballot Numbers”. The Electronic Journal of Combinatorics 24, no. 2 (May 19, 2017): #P2.26. Accessed May 2, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v24i2p26.