@misc{indiciaeb44c600be682,
  title = {Helium concentrations in soil-gas over known petroleum accumulations, WaKeeney area, Trego County, Kansas},
  author = {K.I. Cunningham},
  year = {1987},
  doi = {10.3133/ofr87254},
  url = {https://pubs.usgs.gov/publication/ofr87254},
  note = {Source identifier: ofr87254}
}