@book{HesselerG{\"o}rtz2009,
  author    = {Hesseler, Martin and G{\"o}rtz, Marcus},
  title     = {ERP-Systeme im Einsatz},
  publisher = {W3L-Verlag},
  address   = {Herdecke},
  isbn      = {978-3-86834-006-8},
  pages     = {VII, 287},
  year      = {2009},
  language  = {de}
}
@article{Hesseler2009,
  author    = {Hesseler, Martin},
  title     = {Customizing von ERP-Systemen},
  series = {Controlling \& Management : ZfCM ; Zeitschrift f{\"u}r Controlling \& Management},
  number    = {3},
  issn      = {0931-9077},
  pages     = {8},
  year      = {2009},
  language  = {de}
}