@book{ BA04361773,
  author    = "Fuhrmann, Horst and Reuter, Timothy",
  title     = "Germany in the High Middle Ages, c. 1050-1200",
  publisher = "Cambridge University Press",
  year      = "1986",
  series    = "Cambridge medieval textbooks",
  number    = "",
  URL       = "https://ci.nii.ac.jp/ncid/BA04361773"
}