@misc{indiciae635c2f58cc44,
  title = {The volunteer helps solve group mat class problems.},
  author = {E D FIELD},
  year = {1957},
  doi = {10.1093/ptj/37.8.517},
  url = {https://pubmed.ncbi.nlm.nih.gov/13452833/},
  note = {Source identifier: 13452833}
}