Observadores

• 

  Stefan Bigelow

  https://1231.kr/%ed%94%bc%ec%8b%b1%ec%82%ac%ea%b8%b0-%eb%8b%b9%ec%8b%a0%ec%9d%98-%eb%8f%88%ec%9d%84-%eb%85%b8%eb%a6%ac%eb%8a%94-%ec%82%ac%ec%95%85%ed%95%9c-%ed%95%a8%ec%a0%95/