@misc{indiciaeb1291c951d5c,
  title = {HVO polling telemetry system for low frequency data acquisition; software users' guide},
  author = {T.T. English},
  year = {1987},
  doi = {10.3133/ofr87633},
  url = {https://pubs.usgs.gov/publication/ofr87633},
  note = {Source identifier: ofr87633}
}