Ultrasound-Guided Versus Landmark Technique for Spinal Anesthesia: A Comparative Study of Success Rate, Procedure Time, and Complications. American Journal of Pediatric Medicine and Health Sciences (2993-2149), [S. l.], v. 4, n. 4, p. 28–33, 2026. Disponível em: https://www.grnjournal.us/index.php/AJPMHS/article/view/9342. Acesso em: 25 jun. 2026.