Nicholson T.L., S.L. Campbell, R.B. Hutson, E. Marti, B.J. Bloom, R.L. McNally, W. Zhang, M.D. Barrett, M.S. Safronova, G.F. Strouse, and W.L. Tew, Nature Communications 6, 6896 (2015).
Zhang X., M.N. Bishof, S. Bromley, C.V. Kraus, M.S. Safronova, P. Zoller, A.M. Rey, and J. Ye, Science 345, 1467 (2014).