Warning - the bibtex entry below may be invalid: 
Missing 'booktitle' field 
@inproceedings{AOQModel,
  author = "Karen Petrie with Barbara Smith and Ian Gent",
  journal = "In Proc. International Workshop on Modelling and Solving Problems with Constraints",
  title = "Models and Symmetry Breaking for 'Peaceable Armies of Queens'",
  url = "http://www-users.cs.york.ac.uk/~tw/ecai02/",
  year = "2002",
}