@article{VSchuppan-SCP-2012,
  author  = {Viktor Schuppan},
  title   = {Towards a Notion of Unsatisfiable and Unrealizable Cores for LTL},
  journal = {Science of Computer Programming},
  volume  = {77},
  number  = {7-8},
  year    = {2012},
  pages   = {908-939},
  ee      = {http://dx.doi.org/10.1016/j.scico.2010.11.004},
}