TY - JOUR AU - John Hall BT - IEEE Journal of Selected Topics in Quantum Electronics DA - Jan-11-2000 DO - 10.1109/2944.902162 PY - 2000 SP - 1136 EP - 1144 T2 - IEEE Journal of Selected Topics in Quantum Electronics TI - Optical frequency measurement: 40 years of technology revolutions VL - 6 SN - 1077-260X ER -