@misc{indiciae4e034a95bbac,
  title = {The Wave-Lengths of Secondary X-Rays (Second note).},
  author = {G L Clark and W Duane},
  year = {1923},
  doi = {10.1073/pnas.9.12.419},
  url = {https://pubmed.ncbi.nlm.nih.gov/16586921/},
  note = {Source identifier: 16586921}
}