@book{Alt1980,
  author    = {Alt, Helmut},
  title     = {Allgemeine Elektrotechnik, Nachrichtentechnik, Impulstechnik f{\"u}r UPN-Rechner. (Anwendung programmierbarer Taschenrechner ; 2)},
  publisher = {Vieweg},
  address   = {Braunschweig [u.a.]},
  isbn      = {3-528-04151-X},
  pages     = {VII, 109 S. : graph. Darst.},
  year      = {1980},
  language  = {de}
}
@book{Alt1980,
  author    = {Alt, Helmut},
  title     = {Elektrische Energietechnik, Steuerungstechnik, Elektrizit{\"a}tswirtschaft f{\"u}r UPN-Rechner. (Anwendung programmierbarer Taschenrechner ; 6)},
  publisher = {Vieweg},
  address   = {Braunschweig [u.a.]},
  isbn      = {3-528-04180-3},
  pages     = {VIII, 118 S. : graph. Darst.},
  year      = {1980},
  language  = {de}
}
@book{Alt1986,
  author    = {Alt, Helmut},
  title     = {Finanzmathematik : Algorithmen und praktische Anwendungen; mit Beispielprogrammen zum HP-41},
  publisher = {Vieweg},
  address   = {Braunschweig [u.a.]},
  isbn      = {3-528-04448-9},
  pages     = {XI, 439 S. : graph. Darst.},
  year      = {1986},
  language  = {de}
}
@book{OPUS4-9062,
  title     = {Angewandte Forschung in der Wirtschaftsinformatik},
  editor    = {Wolf, Martin R. and Barton, Thomas and Herrmann, Frank and Meister, Vera G. and M{\"u}ller, Christian and Seel, Christian},
  publisher = {Mana-Buch},
  address   = {Heide},
  isbn      = {978-3-944330-62-4},
  pages     = {259 Seiten},
  year      = {2019},
  language  = {de}
}