@misc{indiciae76d5b3ccf68e,
  title = {A life-cycle description of underground coal mining},
  author = {Lavin, M. L. and Borden, C. S. and Duda, J. R.},
  year = {1978},
  url = {https://ntrs.nasa.gov/citations/19780020643},
  note = {Source identifier: 19780020643}
}