@Electronic{kosfeld2018klausurtraining,
  author = {Kosfeld, Reinhold},
  title  = {Klausurtraining Deskriptive und Induktive Statistik},

  year   = {2018},
  number = {},
  url    = {http://dx.doi.org/10.1007/978-3-658-20455-6},

  const  = {\ text}
}