@misc{indiciaee1b8305c509c,
  title = {Letter: Transfer factor.},
  author = {L E Spitler},
  year = {1973},
  doi = {10.1016/s0140-6736(73)92752-9},
  url = {https://pubmed.ncbi.nlm.nih.gov/4129329/},
  note = {Source identifier: 4129329}
}