Robertson, Aaron, Herbert S. Wilf, and Doron Zeilberger. “Permutation Patterns and Continued Fractions”. The Electronic Journal of Combinatorics 6, no. 1 (October 1, 1999): R38. Accessed April 4, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v6i1r38.