Observateurs

• 

  Jon Jeffery

  https://www.alg-consultant.com/%ec%8a%a4%ed%94%bc%eb%93%9c%ed%82%a4%eb%85%b8-%eb%b6%84%ec%84%9d%ea%b3%bc-%eb%b2%a0%ed%94%bd-%ec%bb%a4%eb%ae%a4%eb%8b%88%ed%8b%b0%ec%9d%98-%ec%97%b0%ea%b3%84%ec%84%b1/