@misc{indiciae35aff42be984,
  title = {Modern vaccines. Practice in developing countries.},
  author = {A J Hall and B M Greenwood and H Whittle},
  year = {1990},
  doi = {10.1016/0140-6736(90)90879-a},
  url = {https://pubmed.ncbi.nlm.nih.gov/1969519/},
  note = {Source identifier: 1969519}
}