@misc{indiciae66e9ccae250d,
  title = {Edge contrast in ionography.},
  author = {D Plewes and H E Johns},
  year = {1978},
  doi = {10.1088/0031-9155/23/6/002},
  url = {https://pubmed.ncbi.nlm.nih.gov/733895/},
  note = {Source identifier: 733895}
}