@misc{indiciaea9a8bc6eee59,
  title = {The perception of transparent three-dimensional objects.},
  author = {D Purves and T J Andrews},
  year = {1997},
  doi = {10.1073/pnas.94.12.6517},
  url = {https://pubmed.ncbi.nlm.nih.gov/9177250/},
  note = {Source identifier: 9177250}
}