TY - JOUR AU - G Wilpers AU - Christopher Oates AU - Scott Diddams AU - A Bartels AU - Tara Fortier AU - Windell Oskay AU - James Bergquist AU - Steven Jefferts AU - Thomas Heavner AU - Thomas Parker AU - Leo Hollberg C2 - Metrologia DA - 2007-03-14 LA - en M1 - 44 PB - Metrologia PY - 2007 TI - Absolute frequency measurement of the neutral 40Ca optical frequency standard at 657 nm based on microkelvin atoms UR - https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50474 ER -