@misc{indiciaef7836472a81f,
  title = {A microcomputer program utilizing a stratigraphic coding system for data entry into the National Coal Resources Data System},
  author = {B.R. Schachte and B.S. Pierce},
  year = {1987},
  doi = {10.3133/ofr87605},
  url = {https://pubs.usgs.gov/publication/ofr87605},
  note = {Source identifier: ofr87605}
}