@misc{indiciae2718d29db5f9,
  title = {Easy to be hard.},
  author = {R Pies},
  year = {1982},
  doi = {10.1016/0021-9681(82)90135-7},
  url = {https://pubmed.ncbi.nlm.nih.gov/7061673/},
  note = {Source identifier: 7061673}
}