@misc{indiciae6e9292e51ac6,
  title = {Second-order perturbation angle techniques for accurately simulating sighting problems of a space sextant},
  author = {Grover, K. C. and Kurkowski, R. L.},
  year = {1965},
  url = {https://ntrs.nasa.gov/citations/19650014781},
  note = {Source identifier: 19650014781}
}