@misc{indiciaeb73dd018b932,
  title = {Preops: a communication technic.},
  author = {C J Kramer},
  year = {1971},
  doi = {10.1016/s0001-2092(07)67348-7},
  url = {https://pubmed.ncbi.nlm.nih.gov/5209708/},
  note = {Source identifier: 5209708}
}