@misc{indiciae126159402e12,
  title = {Windowless X-Ray Tube Spectrometer for Light Element Analysis},
  author = {Davidson, F. D. and Wyckoff, R. W. G.},
  year = {1964},
  url = {https://ntrs.nasa.gov/citations/19640016168},
  note = {Source identifier: 19640016168}
}