@misc{indiciaeda250ed8764f,
  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/19640029421},
  note = {Source identifier: 19640029421}
}