TY - JOUR AU - John Hall BT - in Les Prix Nobel, Royal Academy of Science N1 - JILA Pub. 7936 PY - 2006 T2 - in Les Prix Nobel, Royal Academy of Science TI - Nobel lecture: Defining and measuring optical frequencies UR - http://www.nobelprize.org/nobel_prizes/physics/laureates/2005/hall-lecture.html ER -