“Protective Effect of Surgical Masks Versus N95 Respirator in Prevention of SARS-CoV-2 Contami-Nation in Healthcare Professionals: Systematic Re-View Protocol ”. Principles and Practice of Clinical Research, vol. 8, no. 3, Dec. 2022, pp. 10-18, https://doi.org/10.21801/ppcrj.2022.83.4.