@misc{indiciae7c4a2acda365,
  title = {Circumstances for Pluto-Charon mutual events in 1988},
  author = {Tholen, David J. and Buie, Marc W. and Swift, Catherine E.},
  year = {1987},
  url = {https://ntrs.nasa.gov/citations/19880034263},
  note = {Source identifier: 19880034263}
}