@misc{indiciae51cf67fe6168,
  title = {Proposal for a lunar tunnel-boring machine},
  author = {Allen, Christopher S. and Cooper, David W. and Davila, David, Jr. and Mahendra, Christopher S. and Tagaras, Michael A.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19890008382},
  note = {Source identifier: 19890008382}
}