@inproceedings{Houghton05:solution,
  title = "Solution Equivalent Subquadrangle Reformulations of Constraint Satisfaction Problems",
  author = "Chris Houghton and David A. Cohen",
  year = "2005",
  booktitle = "Proceedings of the 11th International Conference on Principles and Practice of Constraint Programming (CP'05)",
  pages = "851",
  series = "Lecture Notes in Computer Science",
  volume = "3709",
  doi = "10.1007/11564751_89",
}