Nguyen Tien Luc and Tran Thi Khuyen (2020) “Optimization of collagen extraction process from skin of stingray (rajiformes)”, Journal of Technical Education Science, 15(5), pp. 37–43. Available at: https://jte.edu.vn/index.php/jte/article/view/9 (Accessed: 4 June 2026).