Sándor, J. “On the Arithmetical Function \(d_k(n)\)”. Anal. Numér. Théor. Approx. 18, no. 1 (February 1, 1989): 89–94. Accessed November 23, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1989-vol18-no1-art12.