@misc{indiciaefe09c2c896f9,
  title = {Sequential estimation of the state and the observation-error convariance matrix},
  author = {Born, G. H. and Tapley, B. D.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19710039185},
  note = {Source identifier: 19710039185}
}