Violante, Tommaso, and Francesco Saverio Violante. “Surgical Masks Vs Respirators for the Protection Against Coronavirus Infection: State of the Art”. La Medicina del Lavoro | Work, Environment and Health 111, no. 5 (October 31, 2020): 365-371. Accessed January 23, 2021. https://www.mattioli1885journals.com/index.php/lamedicinadellavoro/article/view/9692.