Shi, Xiao-Ting, Fang-Fang Liu, and Feng Qi. “An Integral Representation of the Catalan Numbers”. Global Journal of Mathematical Analysis 3, no. 3 (August 18, 2015): 130–133. Accessed May 4, 2024. https://www.sciencepubco.com/index.php/GJMA/article/view/5055.