@misc{indiciaee6ff2c723e9b,
  title = {GSDRAW and GSMAP version 4.0; prototype programs for the IBM PC and compatible microcomputers to assist compilation and publication of geologic maps and illustrations; C, Source code disk},
  author = {Gary I. Selner and Richard B. Taylor},
  year = {1987},
  doi = {10.3133/ofr87496c},
  url = {https://pubs.usgs.gov/publication/ofr87496C},
  note = {Source identifier: ofr87496C}
}