Ibrahim EL-Zoghby, et al. “Lung Ultrasound Scoring System Vs ROX Index As a Predictor for Progression to the Invasive Mechanical Ventilation in COVID-19 Patients”. Journal of Population Therapeutics and Clinical Pharmacology, vol. 30, no. 5, Mar. 2023, pp. 307-14, https://doi.org/10.47750/jptcp.2023.30.05.031.