@misc{indiciae28774d4f3d2c,
  title = {A plan for validation and verification of Apollo flight computer software},
  author = {Engel, J. S. and Heffron, W. G.},
  year = {1965},
  url = {https://ntrs.nasa.gov/citations/19790073656},
  note = {Source identifier: 19790073656}
}