@misc{indiciaec3d900abbd05,
  title = {An international Mars exploration program},
  author = {Rea, Donald G. and Cunningham, Glenn E. and Craig, Mark K. and Conway, Harold L.},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19900026515},
  note = {Source identifier: 19900026515}
}