@misc{indiciaedf13831a5828,
  title = {Problem families.},
  author = {T G RANKIN},
  year = {1960},
  doi = {10.1016/s0033-3506(60)80085-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/14436191/},
  note = {Source identifier: 14436191}
}