@misc{indiciae4535a4797015,
  title = {Opening the grey box.},
  author = {R J Douglas and K A Martin},
  year = {1991},
  doi = {10.1016/0166-2236(91)90139-l},
  url = {https://pubmed.ncbi.nlm.nih.gov/1719675/},
  note = {Source identifier: 1719675}
}