https://purengom.com/2010/08/02/%eb%8b%b9%ec%8b%a0%ec%9d%98-%eb%b8%94%eb%a1%9c%ea%b7%b8%eb%8a%94-%ec%96%b4%eb%96%bb%ea%b2%8c-%ea%b0%88-%ea%b2%83%ec%9d%b8%ea%b0%80-%eb%b8%94%eb%a1%9c%ea%b7%b8-%eb%b0%a9%ed%96%a5-%ec%84%a4%ec%a0%95/