Effectiveness of Surgical and Cotton Masks in Blocking SARS–CoV-2: A Controlled Comparison in 4 Patients
Annals of Internal Medicine (2020) - Comments
doi: 10.7326/m20-1342  issn: 0003-4819  pubmed: 32251511  issn: 1539-3704 

Seongman Bae, Min-Chul Kim, Ji Yeun Kim, Hye-Hee Cha, Joon Seo Lim, Jiwon Jung, Min-Jae Kim, Dong Kyu Oh, Mi-Kyung Lee, Seong-Ho Choi, Minki Sung, Sang-Bum Hong, Jin-Won Chung, Sung-Han Kim