@misc{indiciaeb2f254f1747f,
  title = {Lighting system for vertical sketchmaster},
  author = {A.R. Leonard},
  year = {1951},
  doi = {10.3133/ofr51126},
  url = {https://pubs.usgs.gov/publication/ofr51126},
  note = {Source identifier: ofr51126}
}