@misc{indiciae62de3a39d893,
  title = {Finite diffeomorphism-invariant observables in quantum gravity.},
  author = {L Smolin},
  year = {1994},
  doi = {10.1103/physrevd.49.4028},
  url = {https://pubmed.ncbi.nlm.nih.gov/10017407/},
  note = {Source identifier: 10017407}
}