@misc{20421,
  author = {John Wright and G Mattingly},
  title = {NIST Calibration Services for Gas Flow Meters: Piston Prover and Bell Prover Gas Flow Facilities},
  year = {1998},
  month = {1998-08-01},
  publisher = {Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NIST.SP.250-49},
  language = {en},
}