@misc{indiciae9db098cfeb32,
  title = {Observation model and parameter partials for the JPL VLBI parameter estimation software MODEST/1991},
  author = {Sovers, O. J.},
  year = {1991},
  url = {https://ntrs.nasa.gov/citations/19920003263},
  note = {Source identifier: 19920003263}
}