@misc{indiciae8ff27a107cd5,
  title = {Double contrast studies.},
  author = {R H Marshak},
  year = {1977},
  doi = {10.2214/ajr.128.5.874},
  url = {https://pubmed.ncbi.nlm.nih.gov/404929/},
  note = {Source identifier: 404929}
}