@book{Stratmann.2001,
  author = {Stratmann, Jörg},
  title = {Bedarfsgerechte Informationsversorgung im Rahmen eines produktlebenszyklusorientierten Controlling},
  publisher = {Eul},
  year = {2001},
  volume = {Bd. 71},
  url = {http://www.gbv.de/dms/hebis-darmstadt/toc/98415638.pdf}
}

@inproceedings{ls_leimeister,
  author = {Berkovich, M. and Leimeister, J. M. and Krcmar, H.},
  title = {Suitability of product development methods for hybrid products as bundles of classic products, software and service elements},
  booktitle = {ASME 2009 - International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE},
  year = {2009},
  note = {145 (29-09)},
  url = {http://pubs.wi-kassel.de/wp-content/uploads/2013/05/JML_181.pdf}
}