@inproceedings{ijcai2009p292,
  title     = {Learning Probabilistic Hierarchical Task Networks to Capture User Preferences},
  author    = {Li, Nan and Kambhampati, Subbarao and Yoon, Sung Wook},
  booktitle = {Proceedings of the Twenty-First International Joint Conference on
               Artificial Intelligence, {IJCAI-09}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Hiroaki Kitano},
  pages     = {1754--1758},
  year      = {2009},
  url       = {https://ijcai.org/proceedings/2009/292},
}