@article{LaeppleMesslingTrabant2011,
  author    = {L{\"a}pple, Dieter and Messling, Markus and Trabant, J{\"u}rgen},
  title     = {Stadt und Urbanit{\"a}t im Zeitalter der St{\"a}dte},
  isbn      = {978-3-86599-127-0},
  year      = {2011},
  language  = {de}
}
@incollection{Trabant2005,
  author    = {Trabant, J{\"u}rgen},
  title     = {Welche Sprache f{\"u}r Europa?},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9938},
  publisher      = {Universit{\"a}t Potsdam},
  year      = {2005},
  language  = {de}
}