Christian, Hans, Mikhael Pramodana Agus, and Derwin Suhartono. 2016. “Single Document Automatic Text Summarization Using Term Frequency-Inverse Document Frequency (TF-IDF)”. ComTech: Computer, Mathematics and Engineering Applications 7 (4):285 -94. https://doi.org/10.21512/comtech.v7i4.3746.