@misc{indiciae24ae565e0073,
  title = {Specific activity estimation on targets immersed in a scattering medium by external collimator counting.},
  author = {T J Callahan and T P Davis},
  year = {1967},
  url = {https://pubmed.ncbi.nlm.nih.gov/6032615/},
  note = {Source identifier: 6032615}
}