@misc{indiciae19a5944d2345,
  title = {Constrained sheath optics for high thrust density, low specific impulse ion thrusters},
  author = {Wilbur, Paul J. and Han, Jian-Zhang},
  year = {1987},
  url = {https://ntrs.nasa.gov/citations/19870052362},
  note = {Source identifier: 19870052362}
}