@misc{indiciaea2ab257adbc4,
  title = {An obstacle to building a time machine.},
  author = {SM Carroll and E Farhi and AH Guth},
  year = {1992},
  doi = {10.1103/physrevlett.68.263},
  url = {https://pubmed.ncbi.nlm.nih.gov/10045847/},
  note = {Source identifier: 10045847}
}