@misc{indiciaec333134cf432,
  title = {Image analysis as a method for determining grain-size distributions in sandstones},
  author = {Michael B. Sawyer},
  year = {1977},
  doi = {10.3133/ofr77280},
  url = {https://pubs.usgs.gov/publication/ofr77280},
  note = {Source identifier: ofr77280}
}