Sushil Chand Verma, Shakti Singhal, Ghanshyam Das Singhal and Gunjan Agrawal (2020) “Comparison of CPAP preoxygenation versus conventional preoxygenation on duration of safe apnoea time in patients undergoing elective surgery under general anaesthesia”, Asian Pacific Journal of Health Sciences, 7(1), pp. 28–39. doi: 10.21276/pjhs.2020.7.1.6.