2020 Masks Timeline WHO’s U-turn Covid-19 Coronavirus Lockdowns Quarantine Curfews Pandemic English Rose YT Channel https://www.youtube.com/watch?v=BOf4cT0zcwo&feature=youtu.be WHO 1 Dec 2020 https://apps.who.int/iris/bitstream/handle/10665/337199/WHO-2019-nCov-IPC_Masks-2020.5-eng.pdf?sequence=1&isAllowed=y WHO 5 June 2020 https://apps.who.int/iris/bitstream/handle/10665/332293/WHO-2019-nCov-IPC_Masks-2020.4-eng.pdf?sequence=1&isAllowed=y WHO 6 April 2020 https://apps.who.int/iris/bitstream/handle/10665/331693/WHO-2019-nCov-IPC_Masks-2020.3-eng.pdf?sequence=1&isAllowed=y WHO 19 March 2020 https://apps.who.int/iris/bitstream/handle/10665/337199/WHO-2019-nCov-IPC_Masks-2020.5-eng.pdf?sequence=1&isAllowed=y 31 March Q & A https://www.who.int/news-room/q-a-detail/coronavirus-disease-covid-19-infection-prevention-and-control-for-health-care-workers Danish Mask Study https://www.acpjournals.org/doi/10.7326/M20-6817