@misc{indiciae511cad148d01,
  title = {Probabilistic time in quantum gravity.},
  author = {M Castagnino},
  year = {1989},
  doi = {10.1103/physrevd.39.2216},
  url = {https://pubmed.ncbi.nlm.nih.gov/9959901/},
  note = {Source identifier: 9959901}
}