@misc{indiciae688218ade632,
  title = {An intractable problem.},
  author = {R Ritch},
  year = {1993},
  doi = {10.1016/s0161-6420(93)31655-6},
  url = {https://pubmed.ncbi.nlm.nih.gov/8459993/},
  note = {Source identifier: 8459993}
}