a Single 199HG+ Ion Optical Clock Bergquist, J. C. ; Diddams, S. A. ; Oates, C. W. ; Curtis, E. A. ; Hollberg, L. ; Drullinger, R. E. ; Itano, W. M. ; Wineland, D. J. ; Udem, Th. Abstract Publication: Laser Spectroscopy Pub Date: June 2002 DOI: 10.1142/9789812778307_0013 Bibcode: 2002lasp.conf..106B