@misc{indiciae79a3abc712f1,
  title = {Bidirectional Continuous Coal Miner},
  author = {Knurovsky, T. and Kkiskis, J. P. and Harris, J.},
  year = {1984},
  url = {https://ntrs.nasa.gov/citations/19830000432},
  note = {Source identifier: 19830000432}
}