Nguyen Hoang Diep, Nguyen Thi Hai Nang, Ngo Thanh Huyen, and Trinh Thi Nhi. “THE RELATED BETWEEN REPRESENT GRAPHS AND THE NUMBER OF IT”. Journal of Applied Science and Technology 9 (April 21, 2020): 44-48. Accessed April 4, 2025. http://jst.utehy.edu.vn/index.php/jst/article/view/300.