@misc{indiciae77e3f01f0d95,
  title = {Interplanetary Trajectory Encke Method /ITEM/ update 12 C program manual},
  author = {Lefton, L. and Whitlock, F.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19680000943},
  note = {Source identifier: 19680000943}
}