@misc{indiciaef7e74cd9866a,
  title = {X-Ray Absorption Toward the Einstein Ring Source PKS 1830-211},
  author = {Mathur, Smita and Nair, Sunita},
  year = {1997},
  url = {https://ntrs.nasa.gov/citations/20030002375},
  note = {Source identifier: 20030002375}
}