Zinellu, Angelo, Andrea De Vito, Valentina Scano, Panagiotis Paliogiannis, Vito Fiore, Giordano Madeddu, Ivana Maida, et al. 2021. “The PaO2 FiO2 Ratio on Admission Is Independently Associated With Prolonged Hospitalization in COVID-19 Patients”. The Journal of Infection in Developing Countries 15 (03):353-59. https://doi.org/10.3855/jidc.13288.