Nguyen Thi Thu, Nguyen Hoang Duong, Pham Quang Minh. RESEARCH ON THE FREE BULGING STAGE IN HYDROSTATIC FORMING PROCESS FOR COPPER SHEET. jst [Internet]. 2022Mar.31 [cited 2025Jan.2];33:87-2. Available from: http://tapchi.utehy.edu.vn/index.php/jst/article/view/527