@incollection{Koch2006,
  author    = {Helmut Koch},
  title     = {Mathematik},
  isbn      = {3-05-003270-7},
  url       = {http://edoc.bbaw.de/oa/series/ren2T0S70UC2/PDF/24L7Ia44iN3YQ_216.pdf},
  year      = {2006},
}