@inbook{Ehrlenspiel_PI_1991,
  title = {Ways to smarter CAD-systems},
  booktitle = {Proceedings of ICED'91Heurista},
  pages = {10-16},
  editors = {Hubka},
  publisher = {Edition},
  address = {Schriftenreihe WDK 21. Zürich},
  year = {1991},
  note = {clmc},
  author = {Ehrlenspiel, K. and Schaal, S.},
  crossref = {p223}
}