@misc{indiciae018d58e2c934,
  title = {UISO; a program for calculation of 230Th-234U-238U isochron ages},
  author = {K.R. Ludwig},
  year = {1993},
  doi = {10.3133/ofr93531},
  url = {https://pubs.usgs.gov/publication/ofr93531},
  note = {Source identifier: ofr93531}
}