@misc{indiciae03da7f5892b4,
  title = {Absorption lines in quasi-stellar objects.},
  author = {Burbidge, E. M. and Burbidge, G. R.},
  year = {1967},
  url = {https://ntrs.nasa.gov/citations/19680034581},
  note = {Source identifier: 19680034581}
}