@misc{indiciae1f9d5101bee4,
  title = {Coal thickness guage using RRAS techniques, parts 2 and 3},
  author = {King, J. D. and Rollwitz, W. L.},
  year = {1980},
  url = {https://ntrs.nasa.gov/citations/19810004013},
  note = {Source identifier: 19810004013}
}