@incollection{WolfZerresZerres,
  author    = {Wolf, Enno and Zerres, Christopher and Zerres, Michael},
  title     = {Kundenbindung},
  series = {Handbuch Marketing-Methodik},
  volume    = {2},
  editor    = {Zerres, Christopher},
  edition   = {2.},
  publisher = {Bookboon},
  address   = {London},
  isbn      = {978-87-403-2274-3},
  pages     = {39 -- 50},
  language  = {de}
}
@incollection{WolfZerresZerres,
  author    = {Wolf, Enno and Zerres, Christopher and Zerres, Michael},
  title     = {Szenario-Technik},
  series = {Handbuch Marketing-Methodik},
  volume    = {1},
  editor    = {Zerres, Christopher},
  edition   = {2.},
  publisher = {Bookboon},
  address   = {London},
  isbn      = {978-87-403-2273-6},
  pages     = {95 -- 110},
  language  = {de}
}
@incollection{WolfZerresZerres,
  author    = {Wolf, Enno and Zerres, Christopher and Zerres, Michael},
  title     = {Delphi-Technik},
  series = {Handbuch Marketing-Methodik},
  volume    = {1},
  editor    = {Zerres, Christopher},
  edition   = {2.},
  publisher = {Bookboon},
  address   = {London},
  isbn      = {978-87-403-2273-6},
  pages     = {111 -- 119},
  language  = {de}
}