@misc{indiciae813c3359ffc3,
  title = {Positron annihilation at the Galactic center},
  author = {Carrigan, B. J. and Katz, J. I.},
  year = {1987},
  url = {https://ntrs.nasa.gov/citations/19880036361},
  note = {Source identifier: 19880036361}
}