@misc{1165666,
  author = {Velma I Burns},
  title = {Standard filters for calibrating photographic exposure meters:},
  year = {1962},
  month = {1962-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.RPT.7704},
  language = {en},
}