@book{ BA11080898,
  author    = "Hassel, Paul",
  title     = "Geschichte der Preussischen Politik 1807 bis 1815",
  publisher = "Zeller",
  year      = "1966",
  series    = "Publicationen aus den k. preussischen Staatsarchiven",
  number    = "Bd. 6",
  URL       = "http://ci.nii.ac.jp/ncid/BA11080898"
}