@inproceedings{costa-branco:2012,
  author    = {Costa, Francisco and Branco, António},
  title     = {Backshift and tense decomposition},
  booktitle = {{Proceedings of the 19th International Conference on Head-Driven Phrase Structure Grammar, Chungnam National University Daejeon}},
  editor    = {Müller, Stefan},
  OPTissn   = {15351793},
  doi       = {10.21248/hpsg.2012.6},
  publisher = {CSLI Publications},
  address   = {Stanford, CA},
  pages     = {86--106},
  year      = {2012},
}

@inproceedings{costa-branco:2012-cr,
  crossref  = {HPSG2012},
  author    = {Costa, Francisco and Branco, António},
  title     = {Backshift and tense decomposition},
  doi       = {10.21248/hpsg.2012.6},
  pages     = {86--106},
}

@proceedings{HPSG2012,
  editor    = {Müller, Stefan},
  title     = {{Proceedings of the 19th International Conference on Head-Driven Phrase Structure Grammar, Chungnam National University Daejeon}},
  booktitle = {{Proceedings of the 19th International Conference on Head-Driven Phrase Structure Grammar, Chungnam National University Daejeon}},
  publisher = {CSLI Publications},
  address   = {Stanford, CA},
  OPTissn   = {15351793},
  year      = {2012},
}