@misc{indiciae59c6c0b799ad,
  title = {Subnarrow linewidth, hole, and split in micromaser spectrum.},
  author = {N Lu},
  year = {1993},
  doi = {10.1103/physrevlett.70.912},
  url = {https://pubmed.ncbi.nlm.nih.gov/10054236/},
  note = {Source identifier: 10054236}
}