Das, M. et al. 2021. Factors affecting the outcome of the usage of high-flow nasal cannula on severe or critically ill COVID-19 patients: a multicentric study from a developing nation. Asian Journal of Medical and Biological Research. 7, 3 (Sep. 2021), 260–272. DOI:https://doi.org/10.3329/ajmbr.v7i3.56136.