@misc{indiciae6bdab34cd4f1,
  title = {Enhancing space transportation: The NASA program to develop electric propulsion},
  author = {Bennett, Gary L. and Watkins, Marcus A. and Byers, David C. and Barnett, John W.},
  year = {1990},
  url = {https://ntrs.nasa.gov/citations/19910009868},
  note = {Source identifier: 19910009868}
}