https://blog.gongquiz.com/2021/02/22/%ec%84%9c%ed%9a%a8%ec%98%81%ec%9d%98-%ed%83%81%ea%b5%ac%eb%a0%88%ec%8a%a8-how-to-pingpong-13%ed%99%94-%eb%94%94%ed%8e%9c%ec%8a%a4%ed%8e%b8-%e3%83%81/
[서효영의 탁구레슨] HOW TO PINGPONG 13화 '디펜스'편 チ