@misc{indiciae8b6729a96a59,
  title = {Quaternion normalization in additive EKF for spacecraft attitude determination},
  author = {Bar-Itzhack, I. Y. and Deutschmann, J. and Markley, F. L.},
  year = {1991},
  url = {https://ntrs.nasa.gov/citations/19910065046},
  note = {Source identifier: 19910065046}
}