@misc{134171,
  author = {Michael McCaleb},
  title = {A Conceptual Data Model of Datum Systems},
  year = {1999},
  number = {104},
  month = {1999-09-23},
  publisher = {Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD},
  language = {en},
}