@misc{indiciae2874dfea640d,
  title = {Development of an electrostatic propulsion engine using sub-micron powders as the reaction mass},
  author = {Herbert, F. and Kendall, K. R.},
  year = {1991},
  url = {https://ntrs.nasa.gov/citations/19910016741},
  note = {Source identifier: 19910016741}
}