@misc{1196206,
  author = {George Kamas and George Kamas and Sandra L Howe},
  title = {Time and frequency users manual:},
  year = {1990},
  month = {1990-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NIST.SP.559r1},
  language = {en},
}