@misc{indiciae40ee9e3e751a,
  title = {Unstained negative image patterns. A checkpoint for quality slides.},
  author = {E S Head and E H Tschen},
  year = {1982},
  doi = {10.1097/00000372-198204000-00008},
  url = {https://pubmed.ncbi.nlm.nih.gov/6179434/},
  note = {Source identifier: 6179434}
}