@book{JoernKlausKlaus2019,
  author    = {Littkemann J{\"o}rn and Derfuß Klaus and Schulte Klaus},
  title     = {{\"U}bungen zum Controlling, Band 1},
  editor    = {J{\"o}rn Littkemann},
  isbn      = {978-3-7347-8833-8},
  year      = {2019},
}