Ortega , Jose Mari E., and Rolito G. Eballe. “A Mathematical Approach on Harmonic Centrality and Centralization of Some Graph Products”. Research and Applications Towards Mathematics and Computer Science Vol. 1 (May 27, 2023): 164–179. Accessed July 2, 2026. https://stm.bookpi.org/RATMCS-V1/article/view/10719.