@misc{indiciaef8464e8f73ff,
  title = {Early warning systems: do they work?},
  author = {P Walker},
  year = {1991},
  doi = {10.1177/00494755910210s102},
  url = {https://pubmed.ncbi.nlm.nih.gov/1882432/},
  note = {Source identifier: 1882432}
}