@misc{indiciaec70ac9dea4cc,
  title = {Observer error.},
  author = {C M FLETCHER},
  year = {1954},
  doi = {10.1016/s0140-6736(54)91283-0},
  url = {https://pubmed.ncbi.nlm.nih.gov/13118779/},
  note = {Source identifier: 13118779}
}