@article{tractablequeryansweringandoptimization,
  title = {Tractable Query Answering and Optimization for Extensions of Weakly-Sticky Datalog+-},
  author = {Mostafa Milani and Leopoldo Bertossi},
  year = {2015},
  eprint = {1504.03386},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1504.03386v1},
}