“Gutman, Sombor, and Harmonic Indices of Unit Graphs in The Integer Ring Modulo With A Specific Order”. Jurnal Matematika, Statistika dan Komputasi 21, no. 3 (May 14, 2025): 725–738. Accessed August 20, 2026. https://journal-598.unhas.ac.id/index.php/jmsk/article/view/43144.