@misc{indiciaed34ef3fd3b92,
  title = {SYTLYN - a program for sight line calculation.},
  author = {R F Penn and D G Davies},
  year = {1973},
  doi = {10.1016/0003-6870(73)90009-4},
  url = {https://pubmed.ncbi.nlm.nih.gov/15677115/},
  note = {Source identifier: 15677115}
}