@inproceedings{conf/kr/KontchakovK16,
  title = "On expressibility of non-monotone operators in {SPARQL}",
  author = "Roman Kontchakov and Egor V. Kostylev",
  year = "2016",
  booktitle = "Proceedings of the 15th International Conference on Principles of Knowledge Representation and Reasoning ({KR} 2016), Cape Town, South Africa, April 25-29, 2016",
  pages = "369--379",
  publisher = "{AAAI} Press",
}