Lol 
Masks work, eh? Document this https://www.bitchute.com/video/rlWESmrijl8Q/.
Then document the dozens of of videos here https://www.bitchute.com/channel/okiFK5CwQrZS/ that show what's really going on with masks.
And if you want to see the danger of masks... https://www.bitchute.com/video/ypLjmXQoLygi/.
Masks work, eh? Document this https://www.bitchute.com/video/rlWESmrijl8Q/.Then document the dozens of of videos here https://www.bitchute.com/channel/okiFK5CwQrZS/ that show what's really going on with masks.
And if you want to see the danger of masks... https://www.bitchute.com/video/ypLjmXQoLygi/.
WOW you really know good scientific sources! Nature? naaaah! "bitchute"
ROFL
When it's this obvious, it serves as scientific source material. Use your head. How does a scientist determine something? He observes it one way or another.