@misc{indiciae3d8b90a85167,
  title = {Longwall shearer tracking system},
  author = {Poulsen, P. D. and Stein, R. J. and Pease, R. E.},
  year = {1984},
  url = {https://ntrs.nasa.gov/citations/19840025697},
  note = {Source identifier: 19840025697}
}