@conference{206626,
  author = {Thomas Heavner and Steven Jefferts and Elizabeth Donley and Jon Shirley and Thomas Parker},
  title = {Improvements in NIST-F1 and a Resulting Accuracy of &#948;f/f = 0.61 &#215; 10<sup>-15</sup>},
  year = {2004},
  month = {2004-08-23},
  publisher = {Proc. IEEE Intl. Ultrasonics, Ferroelectrics, and Frequency Control Anniversary Joint Conf., Montreal, CA},
  url = {https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50084},
  language = {en},
}