@misc{indiciae3a1c9dd95e47,
  title = {Upper limits for CP 1919 X-ray emission},
  author = {Gruber, D. and Matteson, J. L. and Pelling, M. R. and Peterson, L. E.},
  year = {1970},
  url = {https://ntrs.nasa.gov/citations/19700053154},
  note = {Source identifier: 19700053154}
}