Pramono, Fajar, Didi Rosiyadi, and Windu Gata. “Integrasi N-Gram, Information Gain, Particle Swarm Optimation Di Naïve Bayes Untuk Optimasi Sentimen Google Classroom ”. Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) 3, no. 3 (December 2, 2019): 383 - 388. Accessed July 15, 2020. http://www.jurnal.iaii.or.id/index.php/RESTI/article/view/1119.