@misc{indiciaed7eb6850301b,
  title = {Item bank using sample-free calibration.},
  author = {B Choppin},
  year = {1968},
  doi = {10.1038/219870a0},
  url = {https://pubmed.ncbi.nlm.nih.gov/5673356/},
  note = {Source identifier: 5673356}
}