Nilasinwong L, Kuhapatanakul K. Sums of Reciprocal Triangular Numbers. Prog Appl Sci Tech. [internet]. 2020 Oct. 8 [cited 2026 Oct. 14];10(2):14-7. available from: https://ph02.tci-thaijo.org/index.php/past/article/view/242160