@incollection{KurbelPietsch1989,
  author    = {Kurbel, Karl and Pietsch, Wolfram},
  title     = {Projektmanagementebenen bei evolution{\"a}rer Softwareentwicklung},
  series = {Interaktive betriebswirtschaftliche Informations- und Steuerungssysteme},
  booktitle = {Interaktive betriebswirtschaftliche Informations- und Steuerungssysteme},
  editor    = {Kurbel, Karl and Mertens, Peter and Scheer, August W.},
  publisher = {De Gruyter},
  address   = {Berlin},
  isbn      = {3-11-012100-X},
  doi       = {10.1515/9783110847055-013},
  pages     = {261 -- 285},
  year      = {1989},
  language  = {de}
}
@article{PietschKurbel1989,
  author    = {Pietsch, Wolfram and Kurbel, Karl},
  title     = {Expertensystem-Projekte. Entwicklungsmethodik, Organisation und Management / Kurbel, K., Pietsch, W.},
  series = {Informatik-Spektrum. 12 (1989), H. 2},
  journal   = {Informatik-Spektrum. 12 (1989), H. 2},
  isbn      = {0170-6012},
  pages     = {133 -- 146},
  year      = {1989},
  language  = {de}
}