@misc{indiciae3ccd1c9c0b3b,
  title = {Diving into the unknown.},
  author = {D Grundy and P Penny and L Graham},
  year = {1991},
  doi = {10.1136/bmj.302.6778.670},
  url = {https://pubmed.ncbi.nlm.nih.gov/2021737/},
  note = {Source identifier: 2021737}
}