4.    Somsen, G. A., van Rijn, C., Kooij, S., Bem, R. A. & Bonn, D. Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. Lancet Respir. Med. 2600, 9–10 (2020).
5. Â Â Â Konda, A. et al. Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks. ACS Nano (2020) doi:10.1021/acsnano.0c03252.
6.    Davies, A. et al. Testing the efficacy of homemade masks: would they protect in an influenza pandemic? Disaster Med. Public Health Prep. 7, 413–418 (2013).
7. Â Â Â Sciensano. Fact Sheet COVID-19 disease (SARS-CoV-2 virus). 4, 38 (2020).
8.    Lindsley, W. G., Noti, J. D., Blachere, F. M., Szalajda, J. V. & Beezhold, D. H. Efficacy of face shields against cough aerosol droplets from a cough simulator. J. Occup. Environ. Hyg. 11, 509–518 (2014).