@misc{indiciae13db2c37adc0,
  title = {Negatively correlated external and internal symptom clusters.},
  author = {W A Cassell and J L Richman},
  doi = {10.1097/00006842-196801000-00011},
  url = {https://pubmed.ncbi.nlm.nih.gov/4230392/},
  note = {Source identifier: 4230392}
}