@inproceedings{bobrowchallenges, title={Challenges for qualitative reasoning for engineering design}, author={Bobrow, Daniel G and Klenk, Matthew and de Kleer, Johan and Janssen, Bill and Hanley, John}, booktitle={Proceedings of the 26th Annual Workshop on Qualitative Reasoning (QR12)}, year={2012}, venuetype = {Workshop}, url={http://matthewklenk.com/papers/QR12-Challenges.pdf} }