@book{HellmannHerffs2006,
  author    = {Hellmann, Uwe and Herffs, Harro},
  title     = {Der {\"a}rztliche Abrechnungsbetrug},
  publisher = {Springer-Verlag},
  address   = {Berlin},
  isbn      = {3-540-25691-1},
  pages     = {217 S.},
  year      = {2006},
  language  = {de}
}
@phdthesis{Herffs2002,
  author    = {Herffs, Harro},
  title     = {Der Abrechnungsbetrug des Vertragsarztes},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  isbn      = {3-540-42711-2},
  issn      = {1431-1151},
  doi       = {10.1007/978-3-642-59401-4},
  pages     = {247 S.},
  year      = {2002},
  language  = {de}
}