1. Feng S, Shen C, Xia N, Song W, Fan M., Cowling BJ Rational use of face masks in the COVID-19 pandemic. Lancet Respir Med2020; published online March 2. DOI: https://doi.org/10.1016/S2213-2600(20)30134-X.
2. Leung CC, Lam TH, Cheng KK. Mass making in the COVID-19 epidemic: people need guidance. Lancet2020; published online March 2. DOI: https://doi.org/10.1016/S0140-6736(20)30520-1.
3. WHO. Advice on the use of masks in the community, during home care, and in health care settings in the context of COVID-19, 19 March 2020. https://apps.who.int/iris/rest/bitstreams/1272436/retrieve. (accessed March 30, 2020).
4. CDC. Recommendations for cloth face covers, 3 April 2020. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html. (accessed April 4, 2020).