Woo, HoSung, JaeHong Kim, JaMee Kim, and WonGyu Lee. “Exploring the AI Topic Composition of K-12 Using NMF-Based Topic Modeling”. International Journal on Advanced Science, Engineering and Information Technology 10, no. 4 (August 12, 2020): 1471–1476. Accessed July 22, 2024. https://ijaseit.insightsociety.org/index.php/ijaseit/article/view/12787.