@misc{indiciaef5ca30b82462,
  title = {What is transfer factor?},
  author = {A A Gottlieb and L G Foster and S R Waldman and M Lopez},
  year = {1973},
  doi = {10.1016/s0140-6736(73)90861-1},
  url = {https://pubmed.ncbi.nlm.nih.gov/4126619/},
  note = {Source identifier: 4126619}
}