@misc{indiciae742c2308ab08,
  title = {Preventing the return of smallpox.},
  author = {Joel G Breman and Isao Arita and Frank Fenner},
  year = {2003},
  doi = {10.1056/nejmp025175},
  url = {https://pubmed.ncbi.nlm.nih.gov/12556549/},
  note = {Source identifier: 12556549}
}