Hoang Quoc Tuan, Pham Xuan Hien, and Nguyen Cong Thuat. 2019. “RESEARCH, DESIGN AND MANUFACTURE OF AUTOMATIC LENGTH-BASED SPRING CLASSIFICATION MACHINE ”. UTEHY Journal of Science and Technology 22 (July), 13-17. http://tapchi.utehy.edu.vn/index.php/jst/article/view/35.