TY - GEN AU - Bennett, Gwen E C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1999-01-01 05:01:00 DO - https://doi.org/10.6028/NIST.IR.5082-08 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1999 TI - NIST time and frequency bulletin no. 501: ER -