@misc{1149496,
  author = {Belinda L Collins and Peter J Goodin},
  title = {Visibility of exit directional indicators:},
  year = {1991},
  month = {1991-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NIST.IR.4532},
  language = {en},
}