@misc{indiciae328820296b1a,
  title = {Superconductive magnetic-field-trapping device},
  author = {Hildebrandt, A. F. and Elleman, D. D. and Whitmore, F. C.},
  year = {1965},
  url = {https://ntrs.nasa.gov/citations/19730019978},
  note = {Source identifier: 19730019978}
}