@book{BreidenbachW{\"a}hrisch2016,
  author    = {Breidenbach, Karin and W{\"a}hrisch, Michael},
  title     = {Umsatzerl{\"o}se},
  publisher = {NWB},
  address   = {Herne},
  isbn      = {978-3-482-66641-4},
  pages     = {246},
  year      = {2016},
  language  = {de}
}