@misc{indiciae7e6608c333bb,
  title = {Letter: Biofeedback.},
  author = {E L Macpherson},
  year = {1974},
  doi = {10.1136/bmj.3.5931.627-b},
  url = {https://pubmed.ncbi.nlm.nih.gov/4419841/},
  note = {Source identifier: 4419841}
}