Shaza Khan, Huma Batool, Zeenat Umar. “Comparison Effectiveness of Epidural Catheter by Using Two Techniques Air Versus Saline As Pre-Emptive Analgesia in Obstetric Patients”. Pakistan Journal of Medical & Health Sciences, vol. 18, no. 01, Jan. 2024, p. 747, doi:10.53350/pjmhs02024181747.