Bajjad, A. A., N. Kour, A. Sharma, and M. M. Kak. “Insight on the Usage of Mask With Respect to COVID-19: A Review”. International Journal of Research in Medical Sciences, vol. 8, no. 10, Sept. 2020, pp. 3772-7, doi:10.18203/2320-6012.ijrms20204272.