Recent atomic clock comparisons at NIST L. Lorini, N. Ashby, A. Brusch, S. Diddams, R. Drullinger, E. Eason, T. Fortier, P. Hastings, T. Heavner, D. Hume et al. (9 more) Eur. Phys. J. Special Topics, 163 (2008) 19-35 Published online: 25 October 2008 DOI: 10.1140/epjst/e2008-00807-7