Tanzeela Firdous, Ali Kashif, Sahira Nawaz Khan, Ayesha Waqar, Sufyan Ali, Sumayya Tariq. “Compare the Mean Non Hypoxic Apnea Duration of 20° Head up With Conventional Supine Position During Pre-Oxygenation in Patients Undergoing Elective Surgery”. Pakistan Journal of Medical & Health Sciences 16, no. 07 (August 23, 2022): 397. Accessed August 17, 2024. https://pjmhsonline.com/index.php/pjmhs/article/view/2071.