@misc{indiciaef28c17b3bedf,
  title = {Problems in maintaining immunity to smallpox.},
  author = {A S BENENSON and C H KEMPE and R E WHEELER},
  year = {1952},
  doi = {10.2105/ajph.42.5\_pt\_1.535},
  url = {https://pubmed.ncbi.nlm.nih.gov/14923964/},
  note = {Source identifier: 14923964}
}