Analysis of public opinion sentiment against COVID-19 in Indonesia on twitter using the k-nearest neighbor algorithm and decision tree. J. Soft Comput. Explor. [网际网络]. 2022年9月30日 [见引于 2026年8月26日];3(2):117-22. 载于: https://shmpublisher.com/index.php/joscex/article/view/88