@misc{indiciaecff17e43b9ab,
  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/19920004874},
  note = {Source identifier: 19920004874}
}