Guo, Victor J. W., and Jiang Zeng. “Combinatorial Proof of a Curious $q$-Binomial Coefficient Identity”. The Electronic Journal of Combinatorics 17, no. 1 (February 8, 2010): N13. Accessed March 30, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v17i1n13.