@misc{indiciae8e5dc8468abc,
  title = {Positronium formation using the multichannel Schwinger variational principle.},
  author = {U Roy and P Mandal},
  year = {1993},
  doi = {10.1103/physreva.48.233},
  url = {https://pubmed.ncbi.nlm.nih.gov/9909592/},
  note = {Source identifier: 9909592}
}