@book{AltensenAltSchumny1983,
  author    = {Altensen, Frank and Alt, Helmut and Schumny, Harald},
  title     = {Kryptologie (HP-41 C/CV) : Chiffrierung, Textverschl{\"u}sselung, Datenschutz, Morsealphabet (Vieweg-Programmbibliothek Taschenrechner ; 7) / Helmut Alt ; Harald Schumny [Hrsg.]},
  publisher = {Vieweg + Teubner},
  address   = {Wiesbaden},
  isbn      = {3-528-04256-7},
  pages     = {V, 92 S.},
  year      = {1983},
  language  = {de}
}