@misc{indiciae7b72a8f36e40,
  title = {An electronic blaster for use in refraction seismology},
  author = {F.G. Fischer},
  year = {1990},
  doi = {10.3133/ofr90429},
  url = {https://pubs.usgs.gov/publication/ofr90429},
  note = {Source identifier: ofr90429}
}