@misc{PierHummenStellberg1996,
  author    = {Pier, Arnold and Hummen, J{\"o}rg and Stellberg, Michael},
  title     = {Chirurgischer Klammerapplikator},
  pages     = {4 Bl., 7 S. : graph. Darst.},
  year      = {1996},
  language  = {de}
}
@misc{Polaczek1983,
  author    = {Polaczek, Christa},
  title     = {Kofaser - Kategorien und differentielle Algebren},
  publisher = {Math. Inst. der Univ.},
  address   = {Bonn},
  pages     = {178 S. : Anh.},
  year      = {1983},
  language  = {de}
}