@article{4493,
  author = {L.-S. Ma and John Hall},
  title = {Optical heterodyne spectroscopy enhanced by an external optical cavity: toward improved working standards},
  year = {1990},
  journal = {IEEE Journal of Quantum Electronics},
  volume = {26},
  pages = {2006-2012},
  month = {Dec-31-1969},
  issn = {00189197},
  doi = {10.1109/3.62120},
}