《Improving Algorithm Accuracy K-Nearest Neighbor Using Z-Score Normalization and Particle Swarm Optimization to Predict Customer Churn》. Journal of Soft Computing Exploration 1, no. 1 (十月 6, 2020): 56–62. 见于 八月 25, 2026. https://shmpublisher.com/index.php/joscex/article/view/7.