https://www.gov.uk/government/publications/potential-impact-of-face-covering-on-the-transmissibility-of-sars-cov-2-in-the-uk-20-april-2020?utm_source=16d34847-8104-4807-acda-9d3bbbbcff62&utm_medium=email&utm_campaign=govuk-notifications&utm_content=immediate
Paper prepared by Imperial College.
face coveringpotentialimpacttransmissibilitysars