@misc{1200411,
  author = {Kathryn R Stephenson},
  title = {NIST time and frequency bulletin: April:},
  year = {2017},
  month = {2017-04-01 04:04:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NIST.IR.8167-04},
  language = {en},
}