Yangklan*, P., P. Ruengsinsub, and V. Laohakosol. “Unitary Convolution and Generalized MӦbius Function”. CURRENT APPLIED SCIENCE AND TECHNOLOGY, vol. 17, no. 1, Jan. 2018, pp. 1-12, https://li01.tci-thaijo.org/index.php/cast/article/view/128631.