@inbook{587,
  author = {Judah Levine and M. Lombardi and L. Nelson and V. Zhang},
  title = {Technical Reference Manual for NIST Automated Computer Time Service (ACTS)},
  year = {2001},
  url = {http://tf.boulder.nist.gov/general/pdf/1422.pdf},
  note = {JILA Pub. 6977},
}