@article{KerkaKriegesmannSchweringetal.2007,
  author    = {Friedrich Kerka and Bernd Kriegesmann and Markus G. Schwering and Frank Striewe},
  title     = {Innovation requires direction: How to identify the customer problems of tomorrow and possible solutions},
  journal   = {Berichte aus der angewandten Innovationsforschung No 225},
  year      = {2007},
}