Why we need to use and which mask types are effective against the novel coronavirus (COVID-19)?

Jotz, G. P., & Bittencourt, A. G. (2020, July 31). Why we need to use and which mask types are effective against the novel coronavirus (COVID-19)? International Archives of Otorhinolaryngology. Georg Thieme Verlag. https://doi.org/10.1055/s-0040-1713588