@book{ BA62859294,
  author    = "Moran Cruz, Jo Ann Hoeppner and Gerberding, Richard A.",
  title     = "Medieval Worlds : an introduction to European history, 300-1492",
  publisher = "Houghton Mifflin",
  year      = "2004",
  URL       = "http://ci.nii.ac.jp/ncid/BA62859294"
}