@misc{indiciae4bd67012c948,
  title = {Problems of smallpox immunization.},
  author = {A L Libov},
  year = {1967},
  doi = {10.1007/bf02756116},
  url = {https://pubmed.ncbi.nlm.nih.gov/5594850/},
  note = {Source identifier: 5594850}
}