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