@misc{indiciaecffac964a3ef,
  title = {Precise Point Positioning for the Efficient and Robust Analysis of GPS Data From Large Networks},
  author = {Zumberge, J. F. and Heflin, M. B. and Jefferson, D. C. and Watkins, M. M. and Webb, F. H.},
  year = {1997},
  url = {https://ntrs.nasa.gov/citations/19990008059},
  note = {Source identifier: 19990008059}
}