Thực đơn
Khẩu_trang_vảiThực đơn
Khẩu_trang_vảiLiên quan
Tài liệu tham khảo
WikiPedia: Khẩu_trang_vải http://www.nap.edu/catalog/11637 http://akkie.mods.jp/2019-nCoV/images/c/c0/%E3%82%... //doi.org/10.1038%2Fjes.2016.42 //doi.org/10.1136%2Fbmj.h694 //doi.org/10.17226%2F11637 //www.worldcat.org/issn/1559-064X //www.worldcat.org/issn/1756-1833 https://www.cdc.gov/coronavirus/2019-ncov/prevent-... https://www.ceh.org.in/wp-content/uploads/2017/08/... https://web.archive.org/web/20200411102744/https:/...