@misc{indiciaeca3af3b0ff00,
  title = {Extrinsic time in quantum cosmology.},
  author = {SC Beluardi and R Ferraro},
  year = {1995},
  doi = {10.1103/physrevd.52.1963},
  url = {https://pubmed.ncbi.nlm.nih.gov/10019417/},
  note = {Source identifier: 10019417}
}