@misc{indiciae42e3bd774290,
  title = {On-line digitizing: useful mathematical techniques.},
  author = {D J Birnie},
  year = {1983},
  doi = {10.1179/bjo.10.2.78},
  url = {https://pubmed.ncbi.nlm.nih.gov/6573920/},
  note = {Source identifier: 6573920}
}