@misc{indiciaee5ec8ca7a84d,
  title = {Two simple expressions for the spontaneous emission factor beta.},
  author = {van Exter MP and G Nienhuis and JP Woerdman},
  year = {1996},
  doi = {10.1103/physreva.54.3553},
  url = {https://pubmed.ncbi.nlm.nih.gov/9913884/},
  note = {Source identifier: 9913884}
}