@article{Widdau2011,
  author    = {Widdau, Christoph Sebastian},
  title     = {Vorwort},
  isbn      = {978-3-941880-21-4},
  year      = {2011},
  language  = {de}
}
@article{KraemerWiddau2011,
  author    = {Kr{\"a}mer, Raimund and Widdau, Christoph Sebastian},
  title     = {Vorbemerkungen der Herrausgeber},
  isbn      = {978-3-941880-35-1},
  year      = {2011},
  language  = {de}
}