@misc{indiciaeb20dedf302be,
  title = {Numerical Simulation of Two-grid Ion Optics Using a 3D Code},
  author = {Anderson, John R. and Katz, Ira and Goebel, Dan},
  year = {2004},
  url = {https://ntrs.nasa.gov/citations/20070023684},
  note = {Source identifier: 20070023684}
}