@misc{indiciaeca203632601a,
  title = {Letter: Quick test for HBAg using charcoal.},
  author = {S Polak},
  year = {1974},
  doi = {10.1016/s0140-6736(74)93169-9},
  url = {https://pubmed.ncbi.nlm.nih.gov/4131051/},
  note = {Source identifier: 4131051}
}