Muayyad, Indahwati, and Kusman Sadik, “Comparison Study of Distance Methods in Nonlinear Panel Data Clustering with K-Means Method ”, IJSBAR, vol. 62, no. 2, pp. 106–117, May 2022, Accessed: Sep. 11, 2025. [Online]. Available: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/13957