Siddiqui, Muhammad Kamran, N. Nurdin, and Edy Tri Baskoro. “Total Edge Irregularity Strength of the Disjoint Union of Helm Graphs”. Journal of Mathematical and Fundamental Sciences 45, no. 2 (July 1, 2013): 163-171. Accessed January 6, 2026. https://journals.itb.ac.id/index.php/jmfs/article/view/801.