Наблюдатели

• 

  Ralf Ramsden

  https://treewake.com/%EC%9D%BC%EC%88%98-%EB%8C%80%EC%B6%9C-%EB%8B%A8%EA%B8%B0-%EA%B8%88%EC%9C%B5%EC%9D%98-%EC%83%88%EB%A1%9C%EC%9A%B4-%ED%95%B4%EB%8B%B5/