Kuhapatanakul, P. and Laohakosol, V. (2001) “Irrationality of some Series with Rational Terms”, Agriculture and Natural Resources. Bangkok, Thailand, 35(2), pp. 205–209. available at: https://li01.tci-thaijo.org/index.php/anres/article/view/240306 (accessed: 11 October 2026).