@misc{indiciae4270232bf959,
  title = {A simple linear approximation for perturbed motion about moderately elliptic orbits},
  author = {Koble, H. M. and Schneider, A. M.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700068474},
  note = {Source identifier: 19700068474}
}