@misc{indiciae96ecbf3401c3,
  title = {An orbital observation chart.},
  author = {J P Hayter and A W Sugar},
  year = {1991},
  doi = {10.1016/0266-4356(91)90084-i},
  url = {https://pubmed.ncbi.nlm.nih.gov/2049359/},
  note = {Source identifier: 2049359}
}