TY - GEN AU - Michael McCaleb C2 - Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD DA - 1999-09-23 LA - en M1 - 104 PB - Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD PY - 1999 TI - A Conceptual Data Model of Datum Systems ER -