On arithmetical functions related to the Ramanujan sum. - Isao Kiuchi; Yoshio Tanigawa (Period. Math. Hung., 2002)

On the Dirichlet Convolution of Completely Additive Functions. - Isao Kiuchi; Makoto Minamide (J. Integer Seq., 2014)

Sums of Products of Generalized Ramanujan Sums. - Soichi Ikeda; Isao Kiuchi; Kaneaki Matsuoka (J. Integer Seq., 2016)