Sibarani, A. J., and P. Marpaung. “Segmentation Analysis of Countries Based on Human Development Index and Artificial Intelligence Readiness Using Unsupervised Learning Methods: Principal Component Analysis and K-Means Clustering”. Indonesian Journal of Advanced Research, vol. 4, no. 9, Sept. 2025, pp. 1991-02, doi:10.55927/ijar.v4i9.15404.