@book{BaurBurrmannNagel2003,
  author    = {Baur, J{\"u}rgen and Burrmann, Ulrike and Nagel, Michael},
  title     = {Mitgliedschaftsbeziehungen in Sportvereinen},
  year      = {2003},
  language  = {de}
}
@book{BaurBraunBurrmannetal.2003,
  author    = {Baur, J{\"u}rgen and Braun, Sebastian and Burrmann, Ulrike and Nagel, Michael},
  title     = {Wer macht die Vereinspolitik in Sportvereinen?},
  year      = {2003},
  language  = {de}
}