@misc{indiciae36fa11d7d5f4,
  title = {Traversable wormholes: Some simple examples.},
  author = {M Visser},
  year = {1989},
  doi = {10.1103/physrevd.39.3182},
  url = {https://pubmed.ncbi.nlm.nih.gov/9959561/},
  note = {Source identifier: 9959561}
}