@incollection{BaakenvonHagen1986,
  author    = {Baaken, Thomas and von Hagen, Friederike},
  title     = {Marktforschung f{\"u}r technische Produkte},
  series = {Planung und Analyse},
  booktitle = {Planung und Analyse},
  pages     = {S. 251 -- 255.},
  year      = {1986},
  language  = {de}
}