@misc{indiciae5009a9107eed,
  title = {The geometry of avoiding beam intersections and blocking tray collisions.},
  author = {E D Yorke},
  doi = {10.1118/1.596379},
  url = {https://pubmed.ncbi.nlm.nih.gov/2497315/},
  note = {Source identifier: 2497315}
}