@misc{indiciaec315390aa3a1,
  title = {A low-power geophysical data-acquisition system; modification II},
  author = {G.K. Miller},
  year = {1989},
  doi = {10.3133/ofr89153},
  url = {https://pubs.usgs.gov/publication/ofr89153},
  note = {Source identifier: ofr89153}
}