T. Srichan and P. Tangsupphathawat, “On the distribution of primitive roots that are $(k,r)$-integers”, Armen.J.Math., vol. 11, no. 12, pp. 1–12, Dec. 2019, Accessed: Jul. 20, 2026. Available: https://armjmath.sci.am/index.php/ajm/article/view/298