@misc{indiciae5707b4855c4c,
  title = {Optimized observation periods required to achieve geodetic acuracies using the Global Positioning System — Illustration, BHL page 40716631},
  year = {1988},
  url = {https://www.biodiversitylibrary.org/page/40716631},
  note = {Source identifier: page-40716631}
}