Akhtar, Nazia. “The Effects of Entonox and Epidural Analgesia on Arterial Oxygen Saturation of Women in Labour”. Annals of King Edward Medical University 16, no. 3 (May 21, 2011): 150. Accessed April 26, 2024. https://annalskemu.org/journal/index.php/annals/article/view/215.