@misc{indiciaeb8179ef7c3ec,
  title = {Landmark tracking technology},
  author = {Welch, J. D. and Sivertson, W. E. and Wilson, R. G.},
  year = {1975},
  url = {https://ntrs.nasa.gov/citations/19760029872},
  note = {Source identifier: 19760029872}
}