@misc{indiciaeaa4bbd8772e1,
  title = {Miniature Free-Space Electrostatic Ion Thrusters},
  author = {Hartley, Frank T. and Stephens, James B.},
  year = {2006},
  url = {https://ntrs.nasa.gov/citations/20110014141},
  note = {Source identifier: 20110014141}
}