@misc{indiciae2458aa133037,
  title = {A fixed-lag Kalman smoother for retrospective data assimilation},
  author = {Cohn, Stephen E. and Sivakumaran, N. S. and Todling, Ricardo},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/19950036328},
  note = {Source identifier: 19950036328}
}