@misc{indiciae8149e21f707d,
  title = {First-principles calibration of 38Ar tracers :implications for the ages of 40Ar/39Ar fluence monitors},
  author = {Marvin A. Lanphere and G. Brent Dalrymple},
  year = {2000},
  doi = {10.3133/pp1621},
  url = {https://pubs.usgs.gov/publication/pp1621},
  note = {Source identifier: pp1621}
}