S. Supangat, M. Saringat, and M. Rochman, “Predicting Handling Covid-19 Opinion using Naive Bayes and TF-IDF for Polarity Detection”, MATRIK : Jurnal Manajemen, Teknik Informatika dan Rekayasa Komputer, vol. 22, no. 2, pp. 173-184, Mar. 2023.