Наблюдатели

• 

  Porter George

  https://www.natscibooks.com/%ec%8a%a4%ed%8f%ac%ec%b8%a0%ed%86%a0%ed%86%a0%ec%9d%98-%ec%95%88%ec%a0%84%ed%95%9c-%ec%84%a0%ed%83%9d-%ec%8a%88%ec%96%b4%eb%a7%a8-%eb%a8%b9%ed%8a%80%ea%b2%80%ec%a6%9d-%ed%94%8c%eb%9e%ab%ed%8f%bc/