@article{511,
  author = {John Hall and Jun Ye},
  title = {A New Era of Frequency Standards and Optical Frequency Measurement},
  year = {2001},
  journal = {Optics and Photonics News},
  volume = {12},
  pages = {44},
  month = {2001},
  issn = {1047-6938},
  doi = {10.1364/OPN.12.2.000044},
}