@misc{indiciae9582308a9ef1,
  title = {Posttraumatic headache: determining chronicity.},
  author = {R C Packard and L P Ham},
  year = {1993},
  doi = {10.1111/j.1526-4610.1993.hed3303133.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/8486509/},
  note = {Source identifier: 8486509}
}