@misc{indiciaebfbd403e0e1a,
  title = {Economic Notes: opportunity cost.},
  author = {S Palmer and J Raftery},
  year = {1999},
  doi = {10.1136/bmj.318.7197.1551},
  url = {https://pubmed.ncbi.nlm.nih.gov/10356019/},
  note = {Source identifier: 10356019}
}