Arratia, Richard. “On the Stanley-Wilf Conjecture for the Number of Permutations Avoiding a Given Pattern”. The Electronic Journal of Combinatorics 6, no. 1 (August 25, 1999): #N1. Accessed June 15, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v6i1n1.