@misc{indiciae0f91f53882ef,
  title = {A quadtree algorithm to assess line of sight},
  author = {Chamberlain, R. G. and Tailor, E. A. and Gutt, G. M. and Gonzalez, J. E.},
  year = {2003},
  url = {https://ntrs.nasa.gov/citations/20060029346},
  note = {Source identifier: 20060029346}
}