@misc{174441,
  author = {Eyvon Petty},
  title = {Time and Frequency Bulletin},
  year = {2004},
  number = {No. 553},
  month = {2004-01-01},
  publisher = {NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD},
  language = {en},
}