https://skyjournals.org/%eb%8f%99%ec%96%91%ec%9d%98-%eb%b9%9b%eb%82%98%eb%8a%94-%eb%b3%84-%ec%95%84%ec%8b%9c%ec%95%84-%ea%b2%8c%ec%9d%b4%eb%b0%8d%ec%9d%98-%eb%9b%b0%ec%96%b4%eb%82%9c-%ea%b0%95%ec%a0%90%eb%93%a4/