@misc{indiciae49746ef8ccf2,
  title = {The empty delta sign.},
  author = {Emil J Y Lee},
  year = {2002},
  doi = {10.1148/radiol.2243990978},
  url = {https://pubmed.ncbi.nlm.nih.gov/12202715/},
  note = {Source identifier: 12202715}
}