@misc{indiciae6da0aa24181b,
  title = {Three-dimensional gravity and string ghosts.},
  author = {S Carlip and II Kogan},
  year = {1991},
  doi = {10.1103/physrevlett.67.3647},
  url = {https://pubmed.ncbi.nlm.nih.gov/10044789/},
  note = {Source identifier: 10044789}
}