@misc{indiciae106b16e35ca6,
  title = {ANNULAR-BEAM ION ENGINES},
  author = {Anderson, J. R. and Etter, J. E. and Gallagher, H. E.},
  year = {1963},
  url = {https://ntrs.nasa.gov/citations/19630018408},
  note = {Source identifier: 19630018408}
}