@misc{indiciaef87dc7394990,
  title = {General-data plot program for Hewlett-Packard 9830 calculator},
  author = {Herbert H. Stevens and Thomas N. Keefer},
  year = {1975},
  doi = {10.3133/ofr75489},
  url = {https://pubs.usgs.gov/publication/ofr75489},
  note = {Source identifier: ofr75489}
}