@misc{indiciae09beec6b203f,
  title = {Teaching aids.},
  author = {J D Paull},
  year = {1976},
  doi = {10.1177/0310057x7600400409},
  url = {https://pubmed.ncbi.nlm.nih.gov/62519/},
  note = {Source identifier: 62519}
}