@misc{indiciae7d317a7dc8a0,
  title = {A device for automatic photoelectric control of the analytical gap for emission spectrographs},
  author = {John A. Dietrich and Elmo F. Cooley and Kenneth J. Curry},
  year = {1977},
  doi = {10.3133/cir748},
  url = {https://pubs.usgs.gov/publication/cir748},
  note = {Source identifier: cir748}
}