M. Miftahurrahman, I. G. A. Wisnu Wardhana, N. I. Alimon, and N. H. Sarmin, “GRAPH ENERGY OF THE COPRIME GRAPH ON GENERALIZED QUATERNION GROUP”, BAREKENG: J. Math. & App., vol. 20, no. 1, pp. 0031-0040, Nov. 2025.