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