Van-Hau Nguyen, Van-Chien Nguyen, Minh-Tien Nguyen, and Le Chi Ngoc. “EXTRACTIVE SUMMARIZATION AS A GRAPH-BASED PROBLEM”. UTEHY Journal of Applied Science and Technology, Vol. 27, Oct. 2020, pp. 14-20, http://jst.utehy.edu.vn/index.php/jst/article/view/383.