@book{Tietze2008,
  author    = {Tietze, J{\"u}rgen},
  title     = {Einf{\"u}hrung in die angewandte Wirtschaftsmathematik / [Hauptbd.] 14., aktualisierte Aufl.},
  publisher = {Vieweg},
  address   = {Braunschweig},
  isbn      = {978-3-8348-0514-0},
  pages     = {XVI, 566 S. : graph. Darst.},
  year      = {2008},
  language  = {de}
}
@book{Tietze2008,
  author    = {Tietze, J{\"u}rgen},
  title     = {{\"U}bungsbuch zur Finanzmathematik. 5., aktualisierte Aufl.},
  publisher = {Vieweg},
  address   = {Wiesbaden},
  isbn      = {978-3-8348-0442-6},
  pages     = {XII, 410 S. : graph. Darst.},
  year      = {2008},
  language  = {de}
}