@misc{indiciae080407734deb,
  title = {Expanding the input multiplexer for the Data Translation, Inc., model DT2821 analog-to-digital converter},
  author = {J.O. Ellis},
  year = {1989},
  doi = {10.3133/ofr89201},
  url = {https://pubs.usgs.gov/publication/ofr89201},
  note = {Source identifier: ofr89201}
}