@misc{indiciae7df8cfbd87b1,
  title = {GKS-PC; a kernel graphics programming system for IBM-PC and compatible microcomputers},
  author = {R.H. Balay},
  year = {1993},
  doi = {10.3133/ofr93241b},
  url = {https://pubs.usgs.gov/publication/ofr93241B},
  note = {Source identifier: ofr93241B}
}