@misc{indiciae59728259fa08,
  title = {Spacecraft electric propulsion - Now?},
  author = {Barber, T. A. and Edberg, J. R. and Goldsmith, J. V.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19680050915},
  note = {Source identifier: 19680050915}
}