Loci of 3-periodics in an Elliptic Billiard: Why so many ellipses?

@article{Garcia2020LociO3,
  title={Loci of 3-periodics in an Elliptic Billiard: Why so many ellipses?},
  author={Ronaldo Garcia and Jair Koiller and Dan Reznik},
  journal={J. Symb. Comput.},
  year={2020},
  volume={114},
  pages={336-358}
}

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