Al-Khal, R. A., and H. A. Al-Kharsani. “Harmonic Hypergeometric Functions”. Tamkang Journal of Mathematics 37, no. 3 (September 30, 2006): 273–283. Accessed September 27, 2022. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/172.