Ricevuti, Giovanni, Marianno Franzini, and Luigi Valdenassi. “Oxygen-Ozone Immunoceutical Therapy in COVID-19 Outbreak: Facts and Figures”. Ozone Therapy 5, no. 1 (April 10, 2020). Accessed August 8, 2020. https://www.pagepressjournals.org/index.php/ozone/article/view/9014.