@misc{indiciae744409c4423e,
  title = {A computer program in Hewlett-Packard BASIC for plotting and processing U-Pb isotope data on concordia diagrams},
  author = {K.R. Ludwig},
  year = {1979},
  doi = {10.3133/ofr791692},
  url = {https://pubs.usgs.gov/publication/ofr791692},
  note = {Source identifier: ofr791692}
}