@misc{indiciae24d85fd38f9c,
  title = {Coal thickness gauge using RRAS techniques, part 1},
  author = {Rollwitz, W. L. and King, J. D.},
  year = {1978},
  url = {https://ntrs.nasa.gov/citations/19780012630},
  note = {Source identifier: 19780012630}
}