@misc{indiciae47e8c75ef9a9,
  title = {Core drill's bit is replaceable without withdrawal of drill stem - A concept},
  author = {Rushing, F. C. and Simon, A. B.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700000377},
  note = {Source identifier: 19700000377}
}