@misc{indiciaeccb3bfa8f55f,
  title = {Design of double Gauss systems using aspherics.},
  author = {Hopkins, R. E. and Sloan, T. R.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19680053392},
  note = {Source identifier: 19680053392}
}