@misc{indiciaed33bc3c66c3f,
  title = {Do you know your professional fee?},
  author = {W S Apple},
  year = {1967},
  doi = {10.1016/s0003-0465(16)30063-5},
  url = {https://pubmed.ncbi.nlm.nih.gov/6015514/},
  note = {Source identifier: 6015514}
}