@misc{indiciae60a230c5fda7,
  title = {A nurse staffing system based upon assignment difficulty.},
  author = {R B Norby and L E Freund and B Wagner},
  year = {1977},
  doi = {10.1097/00005110-197707090-00001},
  url = {https://pubmed.ncbi.nlm.nih.gov/243004/},
  note = {Source identifier: 243004}
}