@misc{indiciae2de667c6b6af,
  title = {Control groups in research.},
  author = {S I Greenspan},
  year = {1992},
  doi = {10.1097/00004583-199209000-00042},
  url = {https://pubmed.ncbi.nlm.nih.gov/1400142/},
  note = {Source identifier: 1400142}
}