Sibarani, Alexander J.P., and Preddy 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 4, no. 9 (September 29, 2025): 1991–2002. Accessed June 28, 2026. https://journal.formosapublisher.org/index.php/ijar/article/view/15404.