@techreport{VSchuppan-FSEN-2009-full,
  title={Towards a Notion of Unsatisfiable Cores for {LTL}},
  author={V. Schuppan},
  institution={Fondazione Bruno Kessler},
  number={200901000},
  year={2009},
  ee={http://www.schuppan.de/viktor/VSchuppan-FSEN-2009-full.pdf},
  note={Available from \url{http://www.schuppan.de/viktor/VSchuppan-FSEN-2009-full.pdf}},
}