@misc{indiciae0df36cce049f,
  title = {A portable helium sniffer},
  author = {Irving Friedman and E.H. Denton},
  year = {1975},
  doi = {10.3133/ofr75532},
  url = {https://pubs.usgs.gov/publication/ofr75532},
  note = {Source identifier: ofr75532}
}