Improving Algorithm Accuracy K-Nearest Neighbor Using Z-Score Normalization and Particle Swarm Optimization to Predict Customer Churn. J. Soft Comput. Explor. [Internet]. 6 Tháng Mười 2020 [cited 25 Tháng Tám 2026];1(1):56-62. Available at: https://shmpublisher.com/index.php/joscex/article/view/7