@misc{indiciaee2a385f94d28,
  title = {Preliminary tests of annular ion optics},
  author = {Aston, Graeme and Aston, Martha B. and Kolts, James B.},
  year = {1992},
  url = {https://ntrs.nasa.gov/citations/19920066152},
  note = {Source identifier: 19920066152}
}