@inproceedings{ijcai2009p100,
  title     = {A Soft Global Precedence Constraint},
  author    = {Lesaint, David and Mehta, Deepak and O'Sullivan, Barry and Quesada, Luis and Wilson, Nic},
  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     = {566--570},
  year      = {2009},
  url       = {https://ijcai.org/proceedings/2009/100},
}