@article{Freitag1994,
  author    = {Freitag, Thomas},
  title     = {Berliner Lied im Volkston : was ist das?},
  year      = {1994},
  language  = {de}
}
@article{Freitag1994,
  author    = {Freitag, Thomas},
  title     = {Neues Lexikon der Musikp{\"a}dagogik : Personenteil},
  editor    = {Helms, Siegmund and Schneider, Reinhard},
  publisher = {Bosse},
  address   = {Kassel},
  year      = {1994},
  language  = {de}
}
@article{Freitag1994,
  author    = {Freitag, Thomas},
  title     = {Neues Lexikon der Musikp{\"a}dagogik : Sachteil},
  editor    = {Helms, Siegmund and Schneider, Reinhard},
  publisher = {Bosse},
  address   = {Kassel},
  year      = {1994},
  language  = {de}
}