LINH, Đỗ P.; TÚ, N. H. Evaluation of ultrasound-assisted thoracic epidural anesthesia in reducing postoperative pain in patients undergoing upper abdominal surgery: A randomized controlled trial. Journal of Medical Research, [S. l.], v. 138, n. 2, p. 140-147, 2021. DOI: 10.52852/tcncyh.v138i2.88. Disponível em: https://tapchinghiencuuyhoc.vn/index.php/tcncyh/article/view/88. Acesso em: 7 nov. 2026.