@misc{indiciae671ec6120c77,
  title = {The missing balloon sign.},
  author = {R Williams and A M Thomas},
  year = {1987},
  doi = {10.1016/s0009-9260(87)80406-3},
  url = {https://pubmed.ncbi.nlm.nih.gov/3545636/},
  note = {Source identifier: 3545636}
}