@misc{indiciaece52b18c208b,
  title = {Tracking by the Smithsonian astrophysical observatory.},
  author = {Lindquist, C. A. and Whipple, F. L.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19670055507},
  note = {Source identifier: 19670055507}
}