@misc{indiciae10c7b2ce04ea,
  title = {Diatremes with kimberlitic affinities in north-central Montana},
  author = {B. C. Hearn},
  year = {1968},
  doi = {10.1126/science.159.3815.622},
  url = {https://pubs.usgs.gov/publication/70011641},
  note = {Source identifier: 70011641}
}