@book{ BN08555128,
  author    = "Luhmann, Niklas and 佐藤, 勉 ",
  title     = "社会システム理論",
  publisher = "恒星社厚生閣",
  year      = "1993",
  URL       = "https://ci.nii.ac.jp/ncid/BN08555128"
}