https://www.syu.ac.kr/grad/2021%ed%95%99%eb%85%84%eb%8f%84-1%ed%95%99%ea%b8%b0-covid-19%ea%b4%80%eb%a0%a8-%ec%99%b8%ea%b5%ad%ec%9d%b8-%ec%9c%a0%ed%95%99%ec%83%9d-%ec%9e%85%ea%b5%ad-%ec%95%88%eb%82%b4/%ec%9c%a0%ed%95%99%ec%83%9d-%ec%95%88%eb%82%b4-%ec%9e%90%eb%a3%8c001/